Economic Linkages Between Coastal Wetlands and Hunting and Fishing:
   A Review of Value Estimates Reported in the Published Literature




                   Prepared by

               Richard F. Kazmierczak, Jr.
          Associate Professor of Environmental Economics
         Department of Agricultural Economics & Agribusiness
          Louisiana State University Agricultural Center
             Baton Rouge, Louisiana 70803-5604

    http://www.agecon.lsu.edu/faculty_staff/IntroFacPages/kazmierczak.htm




Natural Resource and Environment Committee             Staff Paper 2001-03
LSU Agricultural Economics & Agribusiness                   May 2001
      Economic Linkages Between Coastal Wetlands and Hunting and Fishing:
       A Review of Value Estimates Reported in the Published Literature

                     Richard F. Kazmierczak, Jr.
                 Louisiana State University Agricultural Center


                           Summary

     This manuscript summarizes a total of 12 peer-reviewed studies,1 published from 1978 to 2001,
reporting 32 separate estimates for the disaggregate2 value of hunting and fishing services provided by
coastal and non-coastal wetlands. Estimates ranged across three orders of magnitude and are highly
dependent on the specific geographic site providing the service, the target species of the hunting and
fishing activity, and the measurement technique. Considering only coastal zone wetlands across all study
categories, the value of wetlands to single-target hunting and fishing (oysters, menhaden, etc.) ranged
from $1.05/acre/year to $663.74/acre/year, with a mean and median of $113.95/acre/year and
$10.03/acre/year, respectively. Considering only coastal zone wetlands across all study categories, the
value of wetlands to aggregate hunting or fishing (both commercial and recreational) ranged from
$16.76/acre/year to $1,025.03/acre/year, with a mean and median of $233.37/acre/year and
$106.54/acre/year, respectively. 3, 4 By comparison, the range of reported estimates of willingness-to-pay
(WTP) values for recreational hunting and fishing services were somewhat more narrowly bounded
across studies,5 ranging $83.99 to $616.46, with a mean and median of $303.67 and $207.79,
respectively. The importance of a wetlands geographic location, its relationship to the target fishery or
animals species, and the differing relationships with commercial and recreational consumptive users
suggests that coastal wetland benefits need to be carefully examined within a spatially disaggregated
context.


                          Introduction

     Coastal wetlands are increasingly recognized as essential to natural systems and human activities
because of the environmental services that they provide. However, this recognition has not resulted in
capitalized economic value for landowners (Heimlich et al. 1998). Nonmarketed wetland benefits may be
important to society, but the lack of a market value for the services means that they are often

1
  To the author’s knowledge this represents all the peer-reviewed published studies that explicitly seek to value the
linkage between wetlands and disaggregate hunting and fishing services, both commercial and recreational.
2
  From a theoretical economic perspective, the services provided by wetlands generally should not be disaggregated
and valued separately due to the potential for double counting and offsetting effects (see Pendleton and Shonkwiler
[2001] for a discussion of this in a different context). For example, the provision of hunting and fishing services
may, in many cases, simultaneously provide for increased habitat and species protection. Valuing each of these
services separately (when, in fact, they may be inseparable) and summing will lead to overestimating total potential
wetland value.
3
  All values in year 2000 dollars (see Table 1).
4
  In a partial review of wetland valuation studies, Heimlich et al. (1998) calculated a much broader range on the per
acre value estimates, in part because they considered the provision of a number of different services besides hunting
and fishing, but also because they converted household and individual willingness-to-pay (WTP) values to per acre
values using various assumptions not necessarily contained in the original studies. The review presented in this
manuscript does not take this approach, and instead lists the WTP values separately (if not originally presented on a
per acre basis) for comparison purposes.
5
  Note that the WTP estimates were not, in general, estimated on a per acre basis, and thus should not be directly
compared with the per acre values estimated from non-WTP studies.


                             1
deemphasized relative to physical loss or the private economic gains that can arise from conversion of
wetlands to other land uses (van Vuuren and Roy 1993). While the search for quantitative measures of
wetland values is challenging due to the diversity, socioeconomic context, and complex hydro-biological
functions of wetlands (Scodari 1990), informed policy requires that both market and nonmarket wetland
values be incorporated into the decision making process.

     One important, but only partially marketed, service provided by Louisiana's coastal wetlands is
ecological support for species that are the target of commercial and recreational hunting and fishing.
Dockside revenues for commercial fisheries in Louisiana were $317 million in 1997, which were second
only to Alaska.6 The most important commercial species included shrimp ($144 million), menhaden ($63
million), blue crab ($28 million), and oyster ($30 million). In addition, inshore and offshore fish stocks
support a large recreational sector. In 1996, this sector harvested an estimated 23.4 million pounds of fish
during the 3.14 million trips taken by 607,000 participants. Estimated recreational expenditures totaled
$450 million in 1996, surpassing the value of the commercial fishery. Problems, however, lie in the fact
that little information exists about the relationship between functioning coastal wetland ecosystems and
the related hunting and fishing resources.

     This report documents the current status of knowledge concerning the economic value of the
commercial and recreational hunting and fishing services generated by coastal and other wetlands. In
particular, studies that focus on valuing hunting and fishing services as unbundled products of wetland
function are highlighted.7 A brief overview of the economic linkages between wetland ecosystems and
hunting and fishing is first presented, thus providing a basic framework for understanding why specific
variables and measurement methods are of interest. Second, the common methods used to value services
of wetlands are outlined, along with their major advantages and disadvantages. This information can help
the reader evaluate the usefulness of any particular estimate. Next, the results of individual hunting and
fishing service valuation studies are presented and summarized. Lastly, the report concludes with a
complete list of the literature cited.


             Relationship Between Wetlands and Hunting and Fishing

     Policymakers face complex, multi-objective trade-offs when attempting to develop strategies for
coastal restoration and protection.8 Implementation of any specific strategy will result in benefits and
costs that will, in general, be different than those experienced under alternative strategies. Economics can
be used to help inform policymakers about the relative benefits and cost of different strategies, but
analysts require information on (1) the relationship between anthropogenic activities and coastal wetland
loss, (2) the costs imposed on society from coastal wetland loss, and (3) the costs of taking action to
prevent coastal wetland loss. In the typical environmental management scenario, human activities are
considered to be a cause of degradation, and the management of these activities via regulation or the use
of economic instruments has the goal of reducing environmental impacts. Changing established human
activities is potentially costly, and the cost will vary by the specific type of activity and its
interrelationship with the environment. While some Louisiana coastal wetland loss can be attributed to
traditional human industrial, municipal, and agricultural activities, natural environmental processes on a
regional, hemispheric, and global scale are also important. Complicating the identification of causal
linkages and their importance to hunting and fishing resources is the heterogeneity of existing wetlands.

6
  The statistics reported in this paragraph come from Keithly and Ward (2001).
7
  A substantial part of the wetland valuation literature attempts to measure the theoretically correct multi-product
value of wetlands and not the individual service components. An overview of the results generated by these studies
is presented in the report (Table 2) for comparison to the single-product hunting and fishing value estimates.
8
  The following discussion was adapted from Keithly and Ward (2001) and Heimlich et al. (1998).


                             2
Some wetlands perform many functions, but some may perform few or even none. In addition, many of
the environmental services are generated simultaneously in varying degrees by the same wetland function.
From this perspective, both commercial and recreational hunting and fishing services of wetlands can best
be understood as part of an economic joint product. This jointness-in-products creates difficulties in
measuring the economic importance of specific wetlands functions, and as a result the literature contains a
limited number of empirical studies that isolate the hunting and fishing benefits associated with wetland
integrity.

     Abstracting from the technical measurement difficulties, there a number of general benefits that
accrue to society from its interaction with any large-scale ecosystem such as coastal wetlands (Pearce and
Turner 1990). Ecosystems supply both stock and flow resources that can be used as direct and indirect
inputs to production and consumption activities, thereby generating productivity and growth in the overall
economic system. While the resources can be either renewable or nonrenewable, goods and services
provided by Louisiana's coastal wetlands (and their associated marine ecosystems) are generally
considered renewable resources.9 The provision of hunting and fishing resources via ecological support
processes can be considered one of these renewable resources.

     Wetlands are the most biologically productive ecosystems in the temperate regions, rivaling
tropical rain forests (Mitsch and Gosselink 1993). Their biological productivity derives from an ability to
recycle nutrients and energy, and provide habitat for living organisms.10 Some fish and wildlife species
spend their entire lives in wetlands and others using them intermittently for feeding or reproduction.
Amphibians and reptiles also depend on wetlands, and are particularly sensitive to wetland degradation.
In addition, over one-third of all bird species in North America rely on wetlands for migratory resting
places, breeding or feeding grounds, or cover from predation (Kroodsma 1979). Many fur-bearing
animals, such as muskrat, beaver, otter, mink, and raccoon prefer wetlands as their habitat, and wetland
habitats are critical for the survival of a number of threatened and endangered species. The linkage of
these biophysical functions with economic value comes from the net market and nonmarket value of the
species. Market values are calculated by observing prices and relating them to estimates of production
and harvesting costs, thereby allowing a relatively clear determination of the net economic value of the
harvest attributable to wetlands. Linkages that are less clear are those involving nonmarket valuation,
where estimating the relationship between habitat and nonconsumptive uses is extremely complicated
because of biological, recreational, sociological, and economic considerations that interact in complex
ways. In addition, wetlands policy is complicated by the fact that many wetland goods and services are
public goods whose benefits accrue to society at large or to individuals other than the wetland owners. For
example, a wetland may provide habitat for migratory birds that are targets of hunting, but fail to generate
significant rent for its owner. As a result, many private wetland owners may find it more profitable to
convert wetlands to alternative uses or abandon its maintenance altogether.

     Once the conceptual benefits of an ecosystem are identified, economic values need to be assigned
to these benefits. Having these assigned values allows policy makers to quantitatively assess the
economic benefits that society might gain from marginal improvements in the integrity of the ecosystem.
Value is associated with the amount that society (both current and future generations) would be willing to
pay for the economic system characteristics (primarily the services and attributes) provided by the
ecosystem if they were not provided free of charge. The greater the benefits derived from the services

9
  While significant nonrenewable mineral extraction, and the related economic activity, takes place in coastal
Louisiana and the adjacent continental shelf, to a large extent its continued existence is not dependent on
maintaining the integrity of the coastal wetlands. The extraction industry’s cost structure may change if coastal
wetlands are lost, but not likely to the extent that they would become economically infeasible. Navigation and port
activities, however, are more likely to be negatively affected by the loss of coastal wetlands.
10
  And thus the joint-product link between hunting and fishing resources and the water quality services of wetlands.


                             3
provided by any particular ecosystem, the more that ecosystem is valued by society. In general, the value
of these services tends to be positively related with the integrity of the ecosystem. Of course, any action
taken to decrease the loss of Louisiana’s coastal wetlands, and thus increase the welfare of society at
large, comes with a cost. These costs must be weighed against the benefits to determine, from the criteria
of welfare economics, whether action is warranted, and to what extent.


                       Valuation Methods

     The total economic value of a wetland area is the sum of the amount of money that all people
who benefit from the wetland area would be willing to pay to see it protected (Whitehead 1992). If this
definition of wetland value is to be empirically viable, individuals that benefit must (1) realize that they
benefit, (2) understand the full extent to which they benefit, and (3) be capable of placing a dollar value
on the level of their benefits, either through reference to market-based prices or some alternative,
nonmarket pricing system. Methods for valuing the stock of natural capital assets and service flows
generated by wetlands have been extensively discussed in both the published and unpublished literature.11
While philosophical debate has occurred over the ability to empirically measure the full range of benefits
that flow from an environmental resource, economists generally agree that accurate measurement is
possible if valuation studies are carefully conducted (U.S. Department of Commerce 1993). In fact,
review of past nonmarket valuation studies suggests that previously perceived variability and unreliability
in the estimated values does not actually exist, particularly if one controls for the varying characteristics
of the resources being valued and the way in which the estimated values are presented (Carson et al.
1996). Thus, published value estimates might be useful in analyzing the economic impact of Louisiana's
coastal wetlands as long as careful attention is given to the details of the study and the resources being
valued.12

     Four theoretically plausible valuation methods have been used in the neoclassical economic
literature to place valid dollar values on wetland resources.13 These methods are the net factor income
(NFI) method, the contingent valuation method (CVM), the travel cost method (TCM), and the hedonic
price method (HPM). A fifth set of methods found in the literature, but not theoretically valid under
typical application, is the damage cost or replacement cost methods (DCM or RCM). All of these
methods are briefly described below. In addition, the non-neoclassical literature, as well as the biological
literature, often contains studies employing energy analysis methods (EAM), whereby the value of
ecosystem assets are directly related to their energy processing abilities.14 Shabman and Batie (1978)
detailed the fundamental problems and economic fallacies imbedded in this approach,15 and no further

11
  For excellent early overviews, see Greenley et al. (1982) and Amacher et al. (1989). Scodari (1990) provides a
thorough review of the advantages and disadvantages of various methods specifically within a wetland valuation
context, while Whitehead (1992) contains a lucid, if somewhat terse, review of the methods and the theory behind
them. More recent papers detailing established and newer methods include Feather et al. (1995), Apogee Research,
Inc. (1996), Mahan (1997), Bockstael (1998) and Pendleton and Shonkwiler (2001). For comprehensive reviews of
the theory and application of contingent valuation methods for nonmarket goods and services, see U.S. Department
of Commerce (1993) and Bishop et al. (1998).
12
  This type of detailed examination was beyond the time constraints of this study, but it should be seriously
considered for inclusion in future phases of a valuation project.
13
  The brief methods discussion borrows from Amacher et al. (1989), Whitehead (1992), and others.
14
  This approach, which first received widespread publicity and policy attention due to a study by Gosselink et al.
(1974), is based on the Odum and Odum (1972) contention that society's use of resources should maximize the net
energy production of the total environment (including its natural and developed components).
15
  The fundamental problem is that EAM fails to recognize the nature of the process by which economic values are
determined, and makes an "illegitimate marriage" of the principles of systems ecology with economic theory
(Shabman and Batie 1978). "This leads to estimates of marsh service value that are, at best, inaccurate. At worst,


                             4
discussion of its use is included in this report. The results from two studies employing EAM, however,
are reported in Table 2 in order to completely characterize the wetland valuation literature.

     The NFI method uses market prices to measure the additional profit earned by firms due to the
contribution of the wetlands to production activities, and it generates use values. Thus, the NFI method is
most appropriate when the wetland provides a service that leads to an increase in producer surplus, or the
economic gains attained by the users of the resource, because it exploits the relationship between the
value of the production activity and the wetland acreage. In the NFI method the physical relationship
between wetland areas and the economic activity is empirically estimated from data on the production
activity. It is then possible to identify the increase in producer surplus (economic gain) associated with
the use of the wetland resource.16 If the empirical estimates are obtained through statistical regression,
then estimates of the marginal value product (MVP) of the wetland resource can be generated. In this
context, the MVP provides a direct measure of the firm owner's willingness-to-pay to avoid wetland
degradation.

     Producer surplus generated by the use of a wetland can also be estimated using the RCM. This
approach values the wetland=s service based on the price of the cheapest alternative way of obtaining that
service. For example, the value of a natural wetland in the treatment of wastewater might be estimated
using the cost of chemical, mechanical, or constructive alternatives. The use of RCMs needs to be
governed by three considerations (Shabman and Batie 1978): (1) the alternative considered should
provide the same services, (2) the alternative selected for cost comparison should be the least-cost
alternative, and (3) there should be substantial evidence that the service would be demanded by society if
it were provided by that least-cost alternative. Taken together, these condition differentiate RCM from
the more general class of DCMs, where the entire value of a marketable good or service is tied to the
preservation of a wetland resource, ignoring consumer and producer substitution possibilities. Even with
restrictive application, the RCM can only be considered to yield an upper bound on the true WTP for the
wetland service because the producer may not choose to actually use the alternative considered (Anderson
and Rockel 1991).

     The CVM is a survey approach that measures the total economic value of all wetland goods and
services by directly asking individuals about their WTP. The CVM establishes a hypothetical market by
providing information about wetland resources, specifying payment rules and vehicles, and posing
valuation questions. Answers to these questions can be used to directly measure WTP, and CVM may be
the only way to estimate many non-use values of environmental resources. But, in order for CVM to
yield valid economic measures, study participants must be both willing and able to reveal their values.
Other valuation approaches, such as TCM and HPM discussed below, depend on revealed preferences
through market transactions and other behavior. Statements from economic actors about how they would
act under hypothetical circumstances, as used in the CVM, are a very different measure and ultimately
need to assessed for validity (Bishop et al. 1998). A panel of experts organized by the National Oceanic
and Atmospheric Administration (NOAA) of the U.S. Department of Commerce, and co-chaired by
Nobel laureate economists Kenneth Arrow and Robert Solow, concluded that (1) there is too much
positive evidence to dismiss CVM and its usefulness in providing information about values, (2) CVM
studies do not automatically generate value information, but are highly dependent on the content validity
of the survey, and (3) CVM is an evolving market valuation technique (U.S. Department of Commerce
1993). In the words of the panel (p. 4610), “CV studies convey useful information. We think it is fair to
describe such information as reliable by the standards that seem to be implicit in similar contexts, like

these inaccurate estimates may capture the focus of policy debate, and hinder, rather than improve, the resource
management process for coastal wetlands."
16
  In practice, it is often assumed that the demand for the good being produced by the user is perfectly elastic, and
thus changing wetland services has no effect on consumer surplus.


                              5
market analysis for new and innovative products and the assessment of other damages normally allowed
in court proceedings . . . . Thus, the Panel concludes that CV studies can produce estimates reliable
enough to be a starting point of a judicial process of damage assessment, including lost passive-use
values.”

     The TCM approach is often used to measure the recreational benefits of wetlands, but it is
generally applicable to valuing any nonmarket wetland good or service that individuals are willing to
travel to and use at the wetland site. The TCM method estimates the costs incurred traveling to visit and
use the site, with the concept being that the travel and time costs are measures of implicit market prices.
The estimated costs are then used to construct demand functions that use travel and time costs as
independent variables.17 Consumer surplus per recreation trip and year can then be approximated from
the estimated demand curve. The application of TCM assumes that (1) users have identical utility
functions for the activity, and thus will have identical demand functions, (2) users are indifferent between
incurring costs as user fees or travel costs, (3) weak complimentarity holds in that changes at competing
sites do not affect use at the site being valued, and (4) site use is not congested. Given these assumptions,
TCMs cannot be used to value nonmarket goods and services that either do not require the user to visit the
site or that are offsite products. Furthermore, TCM generally cannot account for multiple sites, visits to
multiple sites on the same trip, or the impact of small resource changes on user perceptions and travel
patterns.

     The HPM has been used to measure the contribution of wetlands for flood control and the role of
wetland aesthetics in housing and property prices. Thus, HPMs attempt to tie wetland service value
directly to a market price (Freeman 1998). In a market at equilibrium, land values and land rents should
be a function of land characteristics, including the proximity to and services provided by wetlands. The
increment to the land or housing price arising from wetland services is a measure of the implicit price of
that service. There are three key assumptions required to apply HPM to estimate the wetland contribution
to land values. First, there must be data on a continuum of sites with varying wetland characteristics and
acreage. Second, purchasers and sellers of wetland parcels are assumed to have access to the same
information regarding the condition of the site and the nature and use of the wetland. Third, wetland
purchasers (or purchasers of property near wetlands) are assumed to have identical preferences for
wetland characteristics. The assumption of identical preferences makes estimation of demand curves
possible when data does not exist about individual preferences.

     The valuation method employed in any particular hunting and fishing service valuation study
depends primarily on the ability to quantitatively discern the biophysical linkages between characteristics
of a particular wetland area and the change in the quality and quantity of hunting and fishing resources.
In cases where this relationship is well understood, NFI methods can be employed. In cases where the
biophysical linkages are not well described, but the demanded hunting and fishing services can be
defined, then RCM or CVM may be most appropriate even in light of their limitations. Given its nature,
recreational hunting and fishing service values are often estimated using TCM approaches. No hunting
and fishing service value studies were found that employed HPM approaches. Of course, the choice of a
particular measurement method is important and can have implications for the estimated value of a
wetland area. For example, in a meta-analysis of wetlands valuation studies, Woodward and Wui (2000)
discovered that NFI methods tended to generate lower estimated values for wetlands than did RCM. This
confirms the Anderson and Rockel (1991) observation that RCM should generate an upper bound on
actual value.



17
  Other independent variables are also employed, including the theoretically requisite income and various potential
demand shifters, depending on the situation being modeled.


                             6
                     Review of Estimated Values

     Peer-reviewed literature estimates of the hunting and fishing service values generated by an acre
of wetland are presented in Table 1. Four different categories of studies were identified; Louisiana
specific studies, other U.S. studies, international studies, and studies that did not report their results on an
area basis (primarily CVM based WTP studies). In addition, peer-reviewed literature estimates of total
service values generated by an acre of wetland were arranged by the same four categories and are
presented in Table 2. The overall service value estimates are potentially useful when evaluating a study,
as individually disaggregated service values should (obviously) never exceed total service value. In fact,
individually disaggregated service values, when summed across all service categories, also should not
exceed total value. In any event, the total values are included in the report to help the reader gain a
broader understanding of the information available in the valuation literature.

     Reported estimates for the value of Louisiana wetlands in the provision of specific hunting and
fishing services ranged from a low of $1.16/acre/year (blue crab) to a high of $18.78/acre/year (shrimp),
with a mean and median value of $10.97/acre/year and $11.97/acre/year, respectively (Table 1).18 The
disparity in valuation can be linked primarily to differences in the markets for specific target species
being investigated. The two existing studies that examined the role of Louisiana wetlands in aggregate
commercial resource production estimated values of $20.90/acre/year for trapping and $43.85/acre/year
for fishing. Given these aggregated service values, the values reported for individual target species
appear plausible (and visa versa). 19

     Studies conducted for wetlands in other regions of the U.S. reported specific hunting and fishing
service values that ranged from $1.05/acre/year (blue crab in Florida) to $663.74/acre/year (oyster at
Northumberland, Virginia), with a mean and median value of $152.28/acre/year and $8.73/acre/year,
respectively (Table 1). While some of the individual estimates fell within the range of values reported for
Louisiana, a number of them were substantially higher. In particular, wetland valuation through
ecological support of Chesapeake Bay oyster production was generally one order of magnitude higher
than the value estimated for Louisiana wetlands, although the Virginia values ranged across two orders of
magnitude. A meta-analysis of the role of wetlands in commercial fishing estimated its value at
$1,025.03/acre/year. The value of wetlands in the U.S. recreational hunting and fishing industry fell
between these extremes, ranging from a low of $8.63/acre/year (muskrat trapping) to $871.39/acre/year
for estuarine-dependent fish species, with a mean and median value of $204.02/acre/year and
$112.17/acre/year, respectively.

     A limited number of international studies reported commercial and recreational hunting and
fishing service values between $16.76/acre/year and $120.84/acre/year, with a mean and median value of
$54.21/acre/year and $25.03/acre/year, respectively. Considering only coastal zone wetlands across all
study categories, the value of wetlands to single-target hunting and fishing (oysters, menhaden, etc.)
ranged from $1.05/acre/year to $663.74/acre/year, with a mean and median of $113.95/acre/year and
$10.03/acre/year, respectively. Considering only coastal zone wetlands across all study categories, the
value of wetlands to aggregate hunting or fishing (both commercial and recreational) ranged from
$16.76/acre/year to $1,025.03/acre/year, with a mean and median of $233.37/acre/year and
$106.54/acre/year, respectively.


18
  All values in year 2000 dollars.
19
  It should be emphasized that all of the reported Louisiana valuation studies were conducted by one set of authors
in a very specific time period. The importance of this information to understanding the value of water quality
services derived from Louisiana wetlands is not clear, although it is always preferable to have multiple, independent
studies on which to base inferences.


                             7
    For comparison purposes, reported estimates of willingness-to-pay (WTP) values for wetland
hunting and fishing services ranged from a low of $83.99 to $616.46, with a mean and median of $303.67
and $207.79, respectively (Table 1). Variability among the WTP estimates was essentially similar to
those generated by the other valuation methods, and they yielded similar valuation levels.




                         8
Table 1. Published estimates of hunting and fishing service values provided by wetlands, 1978-2001.
                               Site              Discount                        Time            NPV        Annualized      Annualized
                 Site             Size                Rate                      Horizon     Base     Estimate      Value/Acre      Value/Acre
                                                                                                             (yr 2000 $)a
 Study     Location    Type    Site Use    (acres)   Valuation Method      (%)                       (years)    Year    (base yr $)      (base yr $)

      ------------------------------------------------------------------------------------------- Louisiana Specific Studies -------------------------------------------------------------------------------------------
Costanza and    Terrebonne      Coastal      Commercial         -----  Secondarily calculated           -----      -----   1983         -----        0.67        1.16
Farber 1987    Parish,       Louisiana     blue crab             marginal value product
          Louisiana               fishery

Costanza and    Terrebonne      Coastal      Commercial         -----  Secondarily calculated           -----      -----   1983         -----        5.80        10.03
Farber 1987    Parish,       Louisiana     menhaden              marginal value product
          Louisiana               fishery

Costanza and    Terrebonne      Coastal      Commercial         -----  Secondarily calculated           -----      -----   1983         -----        8.04        13.90
Farber 1987    Parish,       Louisiana     oyster fishery           marginal value product
          Louisiana

Costanza and    Terrebonne      Coastal      Commercial         -----  Secondarily calculated           -----      -----   1983         -----       10.86        18.78
Farber 1987    Parish,       Louisiana     shrimp fishery           marginal value product
          Louisiana

Costanza and    Terrebonne      Coastal      Commercial         -----  Secondarily calculated           -----      -----   1983         -----       12.09        20.90
Farber 1987,    Parish,       Louisiana     trapping              marginal value product
Costanza et al.  Louisiana
1989

Costanza et al.  Louisiana      Coastal      Commercial         -----  Production function,          8.0 , 3.0    Infinite   1983      317, 846         25.36        43.85
1989                  wetlands     fishing,              marginal value product


     --------------------------------------------------------------------------------------------- Additional U.S. Studies ---------------------------------------------------------------------------------------------
Lynne et al.    Florida Gulf     Coastal      Commercial         -----  Estimated production            10.0     Infinite   1974           3        0.30        1.05
1981        Coast        wetlands     blue crab             function, marginal value
                             fishing              product

Batie and     Accomack,      Coastal      Oyster           -----  Estimated production            10.0     Infinite   1969          11         1.13        5.30
Wilson 1978    Virginia       wetlands     production             function, marginal value
                                               product

Batie and     James City,     Coastal      Oyster           -----  Estimated production            10.0     Infinite   1969          16         1.64        7.70
Wilson 1978    Virginia       wetlands     production             function, marginal value
                                               product




                                                          9
Table 1. Published estimates of hunting and fishing service values provided by wetlands, 1978-2001 – continued.
                               Site              Discount    Time                                 NPV        Annualized       Annualized
                 Site             Size                Rate  Horizon                         Base     Estimate      Value/Acre       Value/Acre
                                                                                                              (yr 2000 $)a
 Study     Location    Type    Site Use    (acres)   Valuation Method      (%)   (years)                         Year    (base yr $)      (base yr $)

      --------------------------------------------------------------------------------------------- Additional U.S. Studies ---------------------------------------------------------------------------------------------
van Vuuren     Lake St. Clair,   Freshwater    Trapping         49.4   Travel cost                 4.0       50   1985          286         5.39         8.63
and Roy 1993    Michigan &      wetlands                  diked
          Canada

Batie and      York, Virginia    Coastal      Oyster           -----  Estimated production           10.0     Infinite   1969          19         1.88         8.82
Wilson 1978               wetlands     production             function, marginal value
                                                product

van Vuuren     Lake St. Clair,   Freshwater    Public hunting      49.4   Travel cost                 4.0       50   1985          567        10.68        17.09
and Roy 1993    Michigan &      wetlands                  diked
          Canada

Batie and      Virginia       Coastal      Oyster           -----  Estimated production           10.0     Infinite   1969          42         4.24        19.89
Wilson 1978     Beach,        wetlands     production             function, marginal value
          Virginia                                  product



van Vuuren     Lake St. Clair,   Freshwater    Public hunting      741    Travel cost                 4.0       50   1985         1,094        20.61        32.98
and Roy 1993    Michigan &      wetlands                undiked
          Canada

van Vuuren     Lake St. Clair,   Freshwater    Angling          741    Travel cost                 4.0       50   1985         2,488        46.87        75.01
and Roy 1993    Michigan &      wetlands                undiked
          Canada

Woodward      -----        Mixed       Bird hunting        -----  Econometric meta-analysis         -----      -----   1990         -----         70        92.23
and Wui 2001                                          of 39 studies yielding per
                                                acre values; excludes WTP                                        90% C.I. of
                                                where per acre value was                                         25 - 197
                                                not generated

                                                                                             981b
Bell 1997      Florida west     Estuarine     Recreational        -----  Estimated production           8.125     Infinite   1984                   79.71        132.11
          coast        saltwater     fishing for             function linked with angler
                     marsh       estuarine              demand function to
                              dependent              calculate consumer surplus
                              species




                                                           10
Table 1. Published estimates of hunting and fishing service values provided by wetlands, 1978-2001 – continued.
                               Site              Discount    Time                                 NPV        Annualized       Annualized
                 Site             Size                Rate  Horizon                         Base     Estimate      Value/Acre       Value/Acre
                                                                                                              (yr 2000 $)a
 Study     Location    Type    Site Use    (acres)   Valuation Method      (%)   (years)                         Year    (base yr $)      (base yr $)

      --------------------------------------------------------------------------------------------- Additional U.S. Studies ---------------------------------------------------------------------------------------------
van Vuuren     Lake St. Clair,   Freshwater    Hunting clubs      370.7   Travel cost                 4.0       50   1985         5,174        97.47        155.99
and Roy 1993    Michigan &      wetlands                  diked
          Canada

van Vuuren     Lake St. Clair,   Freshwater    Hunting clubs       49.4   Travel cost                 4.0       50   1985         6,115       115.20         184.36
and Roy 1993    Michigan &      wetlands                  diked
          Canada

Woodward      -----        Mixed       Recreational        -----  Econometric meta-analysis         -----      -----   1990         -----         357        470.36
and Wui 2001                        fishing               of 39 studies yielding per
                                                acre values; excludes WTP                                        90% C.I. of
                                                where per acre value was                                         95 - 1,342
                                                not generated

Batie and      Westmoreland     Coastal      Oyster           -----  Estimated production           10.0     Infinite   1969         1,072       107.22         503.09
Wilson 1978     Virginia       wetlands     production             function, marginal value
                                                product

Batie and      Northumber-     Coastal      Oyster           -----  Estimated production           10.0     Infinite   1969         1,414       141.46         663.74
Wilson 1978     land, Virginia    wetlands     production             function, marginal value
                                                product

                                                                                            6,471b
Bell 1997      Florida east     Estuarine     Recreational        -----  Estimated production           8.125     Infinite   1984                  525.77         871.39
          coast        saltwater     fishing for             function linked with angler
                     marsh       estuarine              demand function to
                              dependent              calculate consumer surplus
                              species

Woodward      -----        Mixed       Commercial         -----  Econometric meta-analysis         -----      -----   1990         -----         778        1,025.03
and Wui 2001                        fishing               of 39 studies yielding per
                                                acre values; excludes WTP                                        90% C.I. of
                                                where per acre value was                                        108 - 5,618
                                                not generated




                                                           11
Table 1. Published estimates of hunting and fishing service values provided by wetlands, 1978-2001 – continued.
                               Site              Discount    Time                                 NPV        Annualized      Annualized
                 Site             Size                Rate  Horizon                          Base     Estimate       Value/Acre      Value/Acre
                                                                                                              (yr 2000 $)a
 Study     Location    Type    Site Use    (acres)   Valuation Method      (%)   (years)                         Year    (base yr $)      (base yr $)

       --------------------------------------------------------------------------------------------- International Studies ---------------------------------------------------------------------------------------------
                                                                                                                  16.76c
Kosz et al.     Vienna        Danube      Recreational        -----  Prices paid for permits          -----      -----   1991                 14.57 ecu
1992         National Park    floodplain    hunting
                     contained
                     in Park

                                                                                                         21d
Sathirathai     Thailand       Mangrove     Offshore          988   Production function            -----      -----   1993          n.a                  25.03
and Barbier                wetland      fishery, all
2001                            species

Costanza et al.   World wide      Coastal      Food          815 m    Mixed aggregation of            -----      -----   1994          -----        104        120.84
1997                   wetlands     production       world    various studies; little detail
                                           wide    given concerning specific
                                                studies


     ---------------------------------------------------------------------------- Studies Where Value Not Reported on an Area Basis ----------------------------------------------------------------------------
                                                                                                       55.41e g       83.99g
Cooper and      San Joaquin     Seven       Recreational        -----  Travel cost model             -----      -----   1987          -----
Loomis 1991     Valley,       freshwater    waterfowl
           California      wildlife     hunting
                     reserves

                                                                                                     103-323 g    170.71-535.33 g
Farber 1988     Terrebonne      Coastal      Recreational     650,000    Travel cost model, direct         -----      -----   1984          -----
           Parish                 hunting and             WTP, demand function                                              per
           wetlands                fishing               derived consumer surplus                                        household,
                              combined                                                                 depending on
                                                                                                    method and
                                                                                                    assumptions

                                                                                                      131.50 f g       191.41 g
Creel and      San Joaquin     Freshwater    Recreational        -----  Linked site selection and         -----      -----   1988          -----
Loomis 1992     Valley,       recreational   fishing only            trip count models
           California      areas

                                                                                                      154.00 f g       224.17 g
Creel and      San Joaquin     Freshwater    Recreational        -----  Linked site selection and         -----      -----   1988          -----
Loomis 1992     Valley,       recreational   hunting only            trip count models
           California      areas




                                                           12
Table 1. Published estimates of hunting and fishing service values provided by wetlands, 1978-2001 – continued.
                               Site              Discount    Time                            NPV       Annualized      Annualized
                 Site             Size                Rate  Horizon                     Base    Estimate      Value/Acre      Value/Acre
                                                                                                        (yr 2000 $)a
 Study     Location    Type    Site Use    (acres)   Valuation Method      (%)   (years)                     Year    (base yr $)     (base yr $)

     ---------------------------------------------------------------------------- Studies Where Value Not Reported on an Area Basis ----------------------------------------------------------------------------
                                                                                                423.50 f g        616.46 g
Creel and      San Joaquin    Freshwater    Recreational       -----  Linked site selection and        -----     -----   1988         -----
Loomis 1992     Valley,      recreational   hunting and            trip count models
          California     areas      fishing
                            combined
 a
   Study values inflated to common year 2000 values using the Bureau of Labor Statistics (BLS) CPI Inflation Calculator, which bases yearly adjustments on the average consumer price index by year.
 b
   East-west difference due to different WTP estimates and marsh abundance levels.
 c
   Inflated to year 2000 using the BLS CPI Inflation Calculator and converted to U.S. dollars using the ratio 1.10 ecu/$1.00 U.S.
 d
   Under the assumption of a unitary demand elasticity.
 e
   Consumer surplus per hunter day.
 f
   Mean of two differently specified models.
 g
   Value is not reported on a per acre per year basis. In most cases, the value represents household willingness-to-pay for the service where the service/wetland quantity relationship is not defined.




                                                        13
Table 2. Published estimates of total service values provided by wetlands, 1975-2001.
                               Site                                Discount      Time              NPV      Annualized      Annualized
                 Site            Size                                  Rate     Horizon     Base      Estimate     Value/Acre      Value/Acre
                                                                                                             (yr 2000 $)a
 Study     Location    Type     Site Use   (acres)   Valuation Method                        (%)     (years)    Year     (base yr $)     (base yr $)

      ------------------------------------------------------------------------------------------- Louisiana Specific Studies -------------------------------------------------------------------------------------------
Costanza and    Terrebonne      Coastal     Summation      650,000   Simple summation of mixed           8.0     Infinite   1983       586.73         46.94         81.16
Farber 1987    Parish,       Louisiana    of                method estimates of
          Louisiana              commercial            individual services
                            fishing,
                            trapping,
                            recreation,
                            and storm
                            protection

                                                                                                     194.32b
Costanza et al.  Louisiana      Coastal     Commercial        -----  Production function, revenue       8.0 , 3.0    Infinite   1983    2,429 - 8,977                   335.96
1989                  wetlands    fishing,             accounting, travel cost, and
                            trapping,             WTP contingent valuation
                            recreation,
                            and storm
                            protection

Costanza and    Terrebonne      Fresh      All services     650,000   Energy analysis based gross          8.0     Infinite   1983        6,400       512.00         885.20
Farber 1987,    Parish,       coastal                      primary productivity
Costanza et al.  Louisiana      wetlands                     conversion, net value lost
1989                                           when converting wetland to
                                             open water

Costanza and    Terrebonne      Saltwater    All services     650,000   Energy analysis based gross          8.0     Infinite   1983        6,700       536.00         926.70
Farber 1987    Parish,       coastal                      primary productivity
          Louisiana      wetlands                     conversion, net value lost
                                             when converting wetland to
                                             open water

Costanza and    Terrebonne      Brackish    All services     650,000   Energy analysis based gross          8.0     Infinite   1983       10,602        848.16        1,466.40
Farber 1987    Parish,       coastal                      primary productivity
          Louisiana      wetlands                     conversion, net value lost
                                             when converting wetland to
                                             open water




                                                          14
Table 2. Published estimates of total service values provided by wetlands, 1975-2001 -- continued.
                               Site               Discount                       Time            NPV        Annualized      Annualized
                 Site            Size                 Rate                     Horizon    Base     Estimate       Value/Acre      Value/Acre
                                                                                                            (yr 2000 $)a
 Study     Location    Type     Site Use   (acres)   Valuation Method       (%)                      (years)    Year     (base yr $)      (base yr $)

     --------------------------------------------------------------------------------------------- Additional U.S. Studies ---------------------------------------------------------------------------------------------
van Vuuren    Lake St. Clair,   Freshwate    Public and        741   Travel cost                   4.0       50   1985         4,435        83.55        133.71
and Roy 1993   Michigan &      r wetlands   club hunting,    undiked
         Canada                angling,
                           trapping

Gupta and    Massachusetts    LLNN      Benefits of        -----  Average state acquisition            7.0       30   1972          500          40        165
Foster 1975              Wetland     wildlife,             price scaled by habitat score
                           visual/cultur           (wildlife) or quality (visual
                           al, water             cultural), 1971 ACE study of
                           supply, and            Charles River (flood control),
                           flood control           1970 USGS study (supply)

van Vuuren    Lake St. Clair,   Freshwate    Public and       370.7   Travel cost                   4.0       50   1985         6,027        113.54       181.71
and Roy 1993   Michigan &      r wetlands   club hunting,      diked
         Canada                angling,
                           trapping

van Vuuren    Lake St. Clair,   Freshwate    Public and        49.4   Travel cost                   4.0       50   1985         6,968        131.27       210.08
and Roy 1993   Michigan &      r wetlands   club hunting,      diked
         Canada                angling,
                           trapping

Roberts and   Mud Lake,      Fresh      All services       -----  Cost savings, residual return         -----      -----   1995          -----        375       423.72
Leitch 1997   MN-SD        wetland                      to water utilities, contingent
                                            valuation

Gupta and    Massachusetts    HLNN      Benefits of        -----  Average state acquisition            7.0       30   1972         1,400         113        466
Foster 1975              Wetland     wildlife,             price scaled by habitat score
                           visual/cultur           (wildlife) or quality (visual
                           al, water             cultural), 1971 ACE study of
                           supply, and            Charles River (flood control),
                           flood control           1970 USGS study (supply)

Gupta and    Massachusetts    LLNH      Benefits of        -----  Average state acquisition            7.0       30   1972         1,700         137        564
Foster 1975              Wetland     wildlife,             price scaled by habitat score
                           visual/cultur           (wildlife) or quality (visual
                           al, water             cultural), 1971 ACE study of
                           supply, and            Charles River (flood control),
                           flood control           1970 USGS study (supply)


                                                         15
Table 2. Published estimates of total service values provided by wetlands, 1975-2001 -- continued.
                               Site               Discount                      Time             NPV        Annualized      Annualized
                 Site            Size                 Rate                     Horizon     Base     Estimate       Value/Acre      Value/Acre
                                                                                                            (yr 2000 $)a
 Study     Location    Type     Site Use   (acres)   Valuation Method       (%)                     (years)    Year     (base yr $)      (base yr $)
     --------------------------------------------------------------------------------------------- Additional U.S. Studies ---------------------------------------------------------------------------------------------
Gupta and    Massachusetts    MMNM      Benefits of        -----  Average state acquisition            7.0       30   1972         3,000         242        997
Foster 1975              Wetland     wildlife,             price scaled by habitat score
                           visual/cultur           (wildlife) or quality (visual
                           al, water             cultural), 1971 ACE study of
                           supply, and            Charles River (flood control),
                           flood control           1970 USGS study (supply)

Gupta and    Massachusetts    LHNL      Benefits of        -----  Average state acquisition            7.0       30   1972         4,100         330        1,359
Foster 1975              Wetland     wildlife,             price scaled by habitat score
                           visual/cultur           (wildlife) or quality (visual
                           al, water             cultural), 1971 ACE study of
                           supply, and            Charles River (flood control),
                           flood control           1970 USGS study (supply)

Gupta and    Massachusetts    HHNH      Benefits of        -----  Average state acquisition            7.0       30   1972         6,000         484        1,994
Foster 1975              Wetland     wildlife,             price scaled by habitat score
                           visual/cultur           (wildlife) or quality (visual
                           al, water             cultural), 1971 ACE study of
                           supply, and            Charles River (flood control),
                           flood control           1970 USGS study (supply)

Gupta and    Massachusetts    LLLL      Benefits of        -----  Average state acquisition            7.0       30   1972         6,400         519        2,138
Foster 1975              Wetland     wildlife,             price scaled by habitat score
                           visual/cultur           (wildlife) or quality (visual
                           al, water             cultural), 1971 ACE study of
                           supply, and            Charles River (flood control),
                           flood control           1970 USGS study (supply)

Gupta and    Massachusetts    HHLH      Benefits of        -----  Average state acquisition            7.0       30   1972         11,700         943        3,885
Foster 1975              Wetland     wildlife,             price scaled by habitat score
                           visual/cultur           (wildlife) or quality (visual
                           al, water             cultural), 1971 ACE study of
                           supply, and            Charles River (flood control),
                           flood control           1970 USGS study (supply)

Gupta and    Massachusetts    HHMH      Benefits of        -----  Average state acquisition            7.0       30   1972         26,000        2,095       12,750
Foster 1975              Wetland     wildlife,             price scaled by habitat score
                           visual/cultur           (wildlife) or quality (visual
                           al, water             cultural), 1971 ACE study of
                           supply, and            Charles River (flood control),
                           flood control           1970 USGS study (supply)

                                                         16
Table 2. Published estimates of total service values provided by wetlands, 1975-2001 -- continued.
                               Site               Discount                         Time            NPV        Annualized      Annualized
                 Site            Size                 Rate                        Horizon    Base     Estimate       Value/Acre      Value/Acre
                                                                                                               (yr 2000 $)a
 Study     Location    Type     Site Use   (acres)   Valuation Method       (%)                        (years)    Year     (base yr $)      (base yr $)

       --------------------------------------------------------------------------------------------- Additional U.S. Studies ---------------------------------------------------------------------------------------------
Gupta and       Massachusetts    LLHL      Benefits of        -----  Average state acquisition            7.0       30   1972         40,700         3,280       13,512
Foster 1975                Wetland     wildlife,             price scaled by habitat score
                              visual/cultur           (wildlife) or quality (visual
                              al, water             cultural), 1971 ACE study of
                              supply, and            Charles River (flood control),
                              flood control           1970 USGS study (supply)


        --------------------------------------------------------------------------------------------- International Studies ---------------------------------------------------------------------------------------------
Gupta and       Massachusetts    HHHH      Benefits of        -----  Average state acquisition            7.0       30   1972         46,000         3,707       15,271
Foster 1975                Wetland     wildlife,             price scaled by habitat score
                              visual/cultur           (wildlife) or quality (visual
                              al, water             cultural), 1971 ACE study of
                              supply, and            Charles River (flood control),
                              flood control           1970 USGS study (supply)

Thibodeau       Charles River    Costal     All services      8,535   Simple summation of mixed             6    Infinite   1978        171,772      10,306.32        27,220
and Ostro       Basin        wetlands                     method estimates of
1981                                             individual services

                                                                                                                  174.13c
Gren et al.      Danube        Mixed      All           4.3 m   Summation of individual          5.0 and     infinite   1991       3,027 ecu     151.35 ecu
1995         floodplain              ecosystem             service estimates               2.0                         to
                              services                                   percent                     7568 ecu
                                                                                             per acre

Costanza et al.    World wide      Coastal     All services      815 m   Mixed aggregation of various          -----      -----   1994          -----        5,983       6,952
1997                    wetlands    and products      world   studies; little detail given
                                          wide   concerning specific studies

                                                                                                         1,553d
Sathirathai      Thailand       Mangrove    Direct and     988      various                    -----      -----   1993          -----                 1,851
and Barbier                wetland     indirect use
2001                            (timber,
                              fishing,
                              coastline
                              protection)




                                                            17
Table 2. Published estimates of total service values provided by wetlands, 1975-2001 -- continued.
                               Site               Discount                   Time            NPV        Annualized     Annualized
                 Site            Size                 Rate                 Horizon    Base     Estimate      Value/Acre     Value/Acre
                                                                                                      (yr 2000 $)a
 Study     Location    Type     Site Use   (acres)   Valuation Method       (%)                  (years)    Year    (base yr $)      (base yr $)

         ---------------------------------------------------------------------------- Studies Where Value Not Reported on an Area Basis ----------------------------------------------------------------------------


                                                                                                20.77 e       23.47 e
Mullarkey and  Northwest     Fresh      Total value       110   WTP mail survey; respondent         -----     -----   1995         -----
Bishop 1999   Wisconsin     wetland     under high           certainty and scope test
                          certainty            included

                                                                                                57.83 e       65.34 e
Mullarkey and  Northwest     Fresh      Total value       110   WTP mail survey; respondent         -----     -----   1995         -----
Bishop 1999   Wisconsin     wetland     under low            certainty and scope test
                          certainty            included

                                                                                                67.80 e       94.15 e
Pate and     San Joaquin    General     Generalized     90,000   WTP mail survey of Oregon          -----     -----   1989         -----
Loomis 1997   Valley, CA     wetlands    to all uses           residents

                                                                                                 252 e      100.79 e
Loomis et al.  Nebraska      Platte     Wastewater     300,000   WTP mail survey               -----     -----   1998         -----
2000                River      dilution,
                          water
                          purification,
                          erosion
                          control,
                          habitat, and
                          recreation

                                                                                                114.29 e      136.20 e
Stevens et al.  New England    General     Recreation,       -----  WTP contingent valuation          -----     -----   1993         -----
1995                wetlands    rare species,          mail survey
                          food
                          production,
                          flood
                          protection,
                          water supply
                          and pollution
                          control

                                                                                                99.75 e      138.52 e
Pate and     San Joaquin    General     Generalized     90,000   WTP mail survey of             -----     -----   1989         -----
Loomis 1997   Valley, CA     wetlands    to all uses           Washington residents

                                                                                                196.01 e      272.20 e
Pate and     San Joaquin    General     Generalized     90,000   WTP mail survey of Nevada          -----     -----   1989         -----
Loomis 1997   Valley, CA     wetlands    to all uses           residents

                                                                                                210.77 e      292.70 e
Pate and     San Joaquin    General     Generalized     90,000   WTP mail survey California         -----     -----   1989         -----
Loomis 1997   Valley, CA     wetlands    to all uses           residents outside the San
                                          Joaquin Valley

                                                      18
Table 2. Published estimates of total service values provided by wetlands, 1975-2001 -- continued.
                               Site               Discount                    Time            NPV        Annualized     Annualized
                 Site            Size                 Rate                  Horizon    Base     Estimate      Value/Acre     Value/Acre
                                                                                                       (yr 2000 $)a
 Study     Location    Type     Site Use   (acres)   Valuation Method       (%)                   (years)    Year    (base yr $)      (base yr $)

          ---------------------------------------------------------------------------- Studies Where Value Not Reported on an Area Basis ----------------------------------------------------------------------------
                                                                                                 215.55 e      299.34 e
Pate and      San Joaquin    General     Generalized     90,000   WTP mail survey of San           -----     -----   1989         -----
Loomis 1997    Valley, CA     wetlands    to all uses           Joaquin Valley residents
 a
   Study values inflated to common year 2000 values using the Bureau of Labor Statistics (BLS) CPI Inflation Calculator, which bases yearly adjustments on the average consumer price index by year.
 b
   Storm protection accounted for 79 percent ($153.20/acre/yr) of the total value.
 c
   Inflated to year 2000 using the BLS CPI Inflation Calculator and converted to U.S. dollars using the ratio 1.10 ecu/$1.00 U.S.
 d
   Value is strongly influenced by estimates for coastline protection, which account for 96% of the total.
 e
   Value is not reported on a per acre per year basis. In most cases, the value represents household willingness-to-pay for the service where the service/wetland quantity relationship is not defined.




                                                       19
                      Literature Cited

Amacher, G.S., R.J. Brazee, J.W. Bulkley and R.A. Moll. 1989. Application of Wetland Valuation
Techniques: Examples from Great Lakes Coastal Wetlands. Report No. 88-G1569-02, School of Natural
Resources, The University of Michigan and the Institute of Water Research, Michigan State University.

Anderson, R. and M. Rockel. 1991. Economic Valuation of Wetlands. Discussion Paper #065, American
Petroleum Institute, Washington, D.C.

Apogee Research, Inc. 1996. Monetary Measurement of Environmental Goods and Services: Framework
and Summary of Techniques for Corps Planners. IWR Report 96-R-24, U.S. Army Corps of Engineers
Institute for Water Resources, Alexandria, Virginia.

Batie, S.S. and J.R. Wilson. 1978. "Economic Values Attributable to Virginia's Coastal Wetlands as Inputs
in Oyster Production." Southern Journal of Agricultural Economics 10(1):111-118.

Bell, F.W. 1997. "The Economic Valuation of Saltwater Marsh Supporting Marine Recreational Fishing in
the Southeastern United States." Ecological Economics 21:243-254.

Bishop, R.C., P.A. Champ and D.J. Mullarkey. 1998. "Contingent Valuation." In D.W. Bromley (ed.),
The Handbook of Environmental Economics. Cambridge, Massachusetts: Blackwell Publishers Ltd.

Bockstael, N.W. 1998. "Travel Cost Models." In D.W. Bromley (ed.), The Handbook of Environmental
Economics. Cambridge, Massachusetts: Blackwell Publishers Ltd.

Carson, R., N. Flores, K. Martin and J. Wright. 1996. "Contingent Valuation and Revealed Preference
Methodologies: Comparing Estimates for Quasi-Public Goods." Land Economics 72:80-99.

Cooper, J. and J. Loomis. 1991. "Economic Value of Wildlife Resources in the San Joaquin Valley:
Hunting and Viewing Values." In A. Dinar and D. Zilberman (eds.), The Economics and management of
Water and Drainage in Agriculture. Boston, Massachusetts: Kluwer Academic Publishers, pp. 447-462.

Costanza, R. and S. Farber. 1987. "The Economic Value of Wetlands Systems." Journal of Environmental
Management 24:41-51.

Costanza, R., S.C. Farber and J. Maxwell. 1989. "Valuation and Management of Wetland Ecosystems."
Ecological Economics 1:335-361.

Costanza, R., R. d'Arge, R. de Groot, S. Farber, M. Grasso, B. Hannon, K. Limburg, S. Naeem, R.V.
O'neill, J. Paruelo, R.G. Raskin, P. Sutton and M. van den Belt. 1997. "The Value of the World's
Ecosystem Services and Natural Capital." Nature 387:253-260.

Creel, M. and J. Loomis. 1992. "Recreation Value of Water to Wetlands in the San Joaquin Valley:
Linked Multinomial Logit and Count Data Trip Frequency Models." Water Resources Research
28(10):2597-2606.

Farber, S. 1988. “The Value of Coastal Wetlands for Recreation: An Application of Travel Cost and
Contingent Valuation Methodologies.” Journal of Environmental Management 26:299-312.




                          20
Feather, T.D., C.S. Russell, K.W. Harrington and D.T. Capan. 1995. Review of Monetary and
Nonmonetary Valuation of Environmental Investments. IWR Report 95-R-2, U.S. Army Corps of
Engineers Institute for Water Resources, Alexandria, Virginia.

Freeman, A.M. 1998. "Hedonic Pricing Methods." In D.W. Bromley (ed.), The Handbook of
Environmental Economics. Cambridge, Massachusetts: Blackwell Publishers Ltd.

Gosselink, J.G. E.P. Odum and R.M. Pope. 1974. The Value of the Tidal Marsh. Publ. LSU-SG-74-03,
Center for Wetland Resources, Louisiana State University, Baton Rouge, Louisiana.

Greenley, D.A., R.G. Walsh and R.A. Young. 1982. Economic Benefits of Improved Water Quality:
Public Perceptions of Option and Preservation Values. Boulder, Colorado: Westview Press.

Gren, I-M., K-H. Groth and M. Sylven. 1995. "Economic Values of Danube Floodplains." Journal of
Environmental Management 45:333-345.

Gupta, T.R. and J.H. Foster. 1975. "Economic Criteria for Freshwater Wetland Policy in Massachusetts."
American Journal of Agricultural Economics 57:40-45.

Heimlich, R.E., K.D. Wiebe, R. Claassen, D. Gadsby and R.M. House. 1998. Wetlands and Agriculture:
Private Interests and Public Benefits. Agricultural Economic Report No. 765, Resource Economics
Division, Economic Research Service, U.S. Department of Agriculture, Washington, D.C. 94 p.

Keithly, W.R. and J.M. Ward. 2001. “An Economic Perspective of Hypoxia in the Northern Gulf of
Mexico.” In N.N. Rabalais and R.E. Turner (eds.), Coastal Hypoxia: Consequences for Living Resources
and Ecosystems. Washington, DC: Coastal and Estuarine Studies 58, American Geophysical Union.

Kosz, M., B. Brezina and T. Madreiter. 1992. "Kosten-Nuzen Analyse Ausgewahlter Varianten Eines
Nationalparks Danau-Auen." Institute fur Finanzwissenschaft and Infrastrukturpolitik der Technischen
Universitat Wien, Austria.

Kroodsma, D.E. 1979. "Habitat Values for Nongame Wetland Birds." In P.E. Greeson, J.R. Clark and J.E.
Clark (eds.), Wetland Functions and Values -- The State of Our Understanding. Minneapolis, Minnesota:
American Water Resources Association.

Loomis, J., P. Kent, L. Strange, K. Fausch and A. Covich. 2000. "Measuring the Total Economic Value of
Restoring Ecosystem Services in an Impaired River Basin: Results from a Contingent Valuation Survey."
Ecological Economics 33:103-117.

Lynne, G.D., P. Conroy and F.J. Prochaska. 1981. "Economic Valuation of Marsh Areas for Marine
Production Processes." Journal of Environmental Economics and Management 8:175-186.

Mahan, B.L. 1997. Valuing Urban Wetlands: A Property Pricing Approach. IWR Report 97-R-1, U.S.
Army Corps of Engineers Institute for Water Resources, Alexandria, Virginia.

Mitsch, W. J. and J.G. Gosselink. 1993. Wetlands, 2nd Edition. New York: Van Nostrand Reinhold.

Mullarkey, D.J. and R.C. Bishop. 1999. Sensitivity to Scope: Evidence from a CVM Study of Wetlands.
Mimeo. Presented at the American Agricultural Economics Association meetings, Nashville, TN.




                          21
Odum, E.P. and H.T. Odum. 1972. "Natural Areas as Necessary Components of Man's Total
Environment." Transactions of the North American Wildlife and Natural Resources Conference. pp. 178-
189.

Pate, J. and J. Loomis. 1997. "The Effect of Distance on Willingness to Pay Values: A Case Study of
Wetlands and Salmon in California." Ecological Economics 20:199-207.

Pearce, D.W. and R.K. Turner. 1990. Economics of Natural Resources and the Environment. Baltimore,
Maryland: John Hopkins University Press.

Pendleton, L.H. and J.S. Shonkwiler. 2001. "Valuing Bundled Attributes: A Latent Characteristics
Approach." Land Economics 77(1):118-129.

Roberts, L.A. and J.A. Leitch. 1997. Economic Valuation of Some Wetland Outputs of Mud Lake,
Minnesota-South Dakota. Agricultural Economics Report No. 381, Department of Agricultural Economics,
North Dakota State University, October.

Sathirathai, S. and E.B. Barbier. 2001. "Valuing Mangrove Conservation in Southern Thailand."
Contemporary Economic Policy 19(2):109-122.

Scodari, P.F. 1990. Wetlands Protection: The Role of Economics. Environmental Law Institute,
Washington, D.C. 89 pp.

Shabman, L.A. and S.S. Batie. 1978. "Economic Value of Natural Coastal Wetlands: A Critique."
Coastal Zone Management Journal 4(3):231-247.

Stevens, T.H., S. Benin and J.S. Larson. 1995. "Public Attitudes and Economic Values for Wetland
Preservation in New England." Wetlands 15(3):226-231.

Thibodeau, F.R. and B.D. Ostro. 1981. "An Economic Analysis of Wetland Protection." Journal of
Environmental Management 12:19-30.

U.S. Department of Commerce, National Oceanic and Atmospheric Administration. 1993. "Natural
Resource Damage Assessments Under the Oil Pollution Act of 1990." Federal Register 58(10):4601-4614.

van Vuuren, W. and P. Roy. 1993. "Private and Social Returns from Wetland Preservation Versus Those
From Wetland Conversion to Agriculture." Ecological Economics 8:289-305.

Whitehead, J.C. 1992. "Economic Valuation of Wetland Resources: A Review of the Value Estimates."
Journal of Environmental Systems 22(2):151-161.

Woodward, R.T. and Y.S. Wui. 2001. "The Economic Value of Wetland Services: A Meta-Analysis."
Journal of Ecological Economics 37(2):257-270.




                         22