NOAA Technical Memorandum NMFS 

JUNE 1983 

NMFS GUIDELINES ON ECONOMIC 

VALUATION OF MARINE 

RECREATIONAL FISHING 

Daniel D. Huppert 

NOAA-TM-NMFS-SWFC-32 

U.S. DEPARTMENT OF COMMERCE 

National Oceanic and Atmospheric Administration 

National Marine Fisheries Service 

Southwest Fisheries Center 
NOAA Technical Memorandum NMFS 

The National Oceanic and Atmospheric Administration (NOAAI, organized in 1970, hasevolved intoan 

agency which establishes national policies and manages and conserves our oceanic, coastal, and atmospheric resources An organizational element within NOAA. the Office of Fisheries is responsible for 

fisheries policy and the direction of the National Marine Fisheries Service (NMFS) 

In addition to its formal publications, the NMFS uses the NOAATechnical Memorandum series to issue 

informal scientific and technical publicattons when coniplete formal review and editorial processing are 

not appropriate or feasible Documents within this series. however, reflect sound professional work and 

may be referenced in the formal scientific and technical literature. 
NOAA Technical Memorandum NMFS 

inis TM sefle5 15 bsed for docmewition and !Imely communcalion 01 preltminary results. imferim repons. or 

SDeC'a' ?aose inrorn-ar!an an3 lave -01 :ecwea compete forrrai revNew. edltor'al control. or detailed ediling 

JUNE 198

NMFS GUIDELINES ON ECONOMIC 

VALUATION OF MARINE 

RECREATIONAL FISHING 

Daniel D. Huppert 

Southwest Fisheries Center 

National Marine Fisheries Service 

La Jolla, CA 92038 

NOAA-TM-NMFS-SWFC-32 

U.S. DEPARTMENT OF COMMERCE 

Malcolm Baldrige. Secretary 

National Oceanic and Atmospheric Administration 

John V. Byrne, Administrator 

National Marine Fisheries Service 

William G. Gordon, Assistant Administrator for Fisheries 
MRF Evaluation 5/23/83 

NMFS GUIDELINES ON ECONOMIC VALUATION OF MARINE 

RECREATIONAL FISHING 

Daniel D. Huppert 

Southwest Fisheries Center 

La Jolla, Calif. 

T. TNTRODUCTION 

This guideline on marine recreational fishery evaluation is 

intended to serve as an outline for reporting NMFS research and 

fishery managenent information regarding impacts of regulatory 

changes or projects on the quantity or quality of marine 

recreational fishing. It does not serve as a primer on economic 

analysis of recreation, but it does provide a rudimentary 

explanatign of what an economic evaluation of recreation is a11 

about. Throughout the following text I have attempted to use 

simple, common English terms as far as possible. However, to 

discuss a difficult technical problem, such as recreational 

valuation, without using any of the appropriate technical jargon 

would lead to greater misunderstanding. Hence some economic 

training is desirable, if not essential, for any serious attempt 

to implement the eccnomic evaluation approaches described. 

Moreover, the guidelines emphasize the tactics of producing 

a defensible statement of economic value rather than the 

quantitative techniques and theoretical models needed to actually 

measure the value. Consequently, standard works on recreational 

economics are referenced repeatedly. Familiarity with this 

literature is a prerequisite to top quality work. Anong the more 

prominent references are the Water Resources Council Guidelines, 

A. Flyrick Freeman's book, the monograph by J.F. Dwyer, J.R. Kelly 

1 
and M.D. Bowes, and a recent draft, handbook on benefit-cost 

assessment produced by the Research Triangle Institute for the 

Environmental Protection Agency. Full references are listed at 

the end of this document. 

11. SCOPE 

Procedures recommended in this report are appropriate for 

evaluating a variety of proposed rules, regulations or projects 

that incrementally change the quantity or quality of marine 

recreational fishing. Most such changes would stem from public 

decisions affecting the biological environment or the rules of 

access to the mzrine environment. Examples of such decisions 

include: (a) modified access to ocean fishing through 

construction of piers or artificial reefs; (b) changed 

recreational "quality" through fish stock enhancement, mitigation 

of environmental problems, and increased or decreased commercial 

fishing quotas; and (c> altered fishing rules like bag limits, 

gear requirements and area closures. All of these could affect 

the value of marine recreational fishing to the participants. 

Evaluation procedures described herein seek to assign a dollar 

value that is equivalent to the amount recreationists would be 

willing to pay (WTP) for increased marine angling or the amount 

recreationists would be willing to accept in Compensation (WTA) 

for diminished marine angling. 

It is important to note the limitations inherent in the 

scope of this discussion. First, major environmental alterations 

(such as widespread destruction of fisheries habitat or species 

extinction) cannot be completely evaluated by these procedures. 

2 
FlRF Evaluation 5/23/83 

This is because these widespread environmental changes effect 

non-recreationists, as well as recreationists, and because large 

environmental effects may cause substantial redistributions in 

real income among citizens. Second, the procedures do not provide 

estimates of commercial economic impact or of the importance of 

marine recreation to a regional economy. Recreational evaluation 

procedures recommended below seek to develop dollar values 

representing the value of fishing to participants, not income 

generated in associated support industries. The economic impact 

of recreational expenditures on a regional economy, an important 

concern in many cases, may be estimated by use of an regional 

in put - out put mod el . 

Occasionally, gross angler expenditures are incorrectly taken 

as a measure of the economic value of recreational fishing. While 

expenditures are prima facie evidence that recreationists place 

value on fishing and the underlying natural resources, the total 

quantity of such expenditures made on recreational trips is not a 

useful estimate of that value. There are three reasons for this. 

First, many of the expenditures made for equipment, food, 

transportation and lodgings during a fishing-related trip are not 

specifically attributable to fishing. Recreational trips are 

often multi-purpose in nature, and total expenditures are not a 

fair indicator of costs incurred specifically for fishing. 

Second, the total level of such expenditures is largely 

independent of the quality of any specific fishing site. The 

location and composition of the expenditures made by 

recreationists will undoubtedly change when opportunities to fish 

3 
NRF Evaluation 5/23/83 

improve or deteriorate. But to a large extent these changes cause 

compensating losses and gains among different fishing areas and 

among different categories of outdoor recreation. Finally and 

most importantly, to treat expenditures as a measure of value 

involves a simple logical fallacy. Expenditures represent costs 

of fishing. With falling fuel prices, for example, we might 

find striped bass fishermen spending less per fishing trip in 

1983 than in 1981. Should we take this as evidence that striped 

bass fishing has fallen in value? No, just the opposite. With 

lower costs, fishermen are likely to make more fishing trips and 

net economic value of fishing should be even greater. 

Expenditures represent a cost that detracts from the net economic 

value of the recreational experience. It is this net economic 

value which we seek to measure. 

One last point requires emphasis--the value of fishing is 

generally not the same as the value of fish. Fishing, like other 

recreational activities, has many dimensions. While the 

opportunity to catch a fish is an essential elenent, other 

elements are important, too. When we estimate the value of 

fishing, we get the value of a complex mixture of things, not all. 

of which is strictly dependent upon the quantity or quality of 

fish available. Hence the economic value of a fishing day does 

not directly address the question of fish resource value. 

Nevertheless, economic value of a particular fish stock or of a 

prospective change in fish abundance can be estimated using some 

of the techniques suggested below. 

4 
T: I I. CONCEPTUAL BASIS 

MRF Evaluation 5/23/83 

(a) General. Economic benefits accruing from marine 

recreational angling are preferably measured in terms of (1) 

willingness to pay (WTP) for enhanced recreational opportunities, 

or (2) willingness to accept compensation (WTA) for diminished 

recreational opportunities. In most cases the prospective 

recreational fishing impacts will be small enough that the 

distinction between WTP and WTA will be insignificant. Willig 

(1976) provides the theoretical conditions under which the two 

measures of value are approximately the same, and the Limitations 

t9 Willig's analysis are discussed by N. Bockstael and K.E. 

McConnell (1981). When Willig's approximation holds, the ordinary 

'lconsumer's surplus" (OCS), represented as the area under an 

individual's demand curve for recreation above the price, is an 

adequate approximation of economic benefit. In Figure 1 the 

downward sloping curve depicts a typical angler demand function 

for recreational fishing trips. With a price per trip of P1, the 

angler takes 91 trips per year and enjoys a consumer's surplus 

represented by the cross-hatched area labelled "A'!. 

Public policy can affect the level of benefits by changing 

the cost of access to the fishery (represented as a decrease in 

price in Figure 1) or by changing the attractiveness or lfqualityl' 

of the recreational activity. Facilities development, for 

example, may reduce the average cost of fishing trips from P1 to 

P2 as depicted in Figure 1. Angler's respond to this decrease by 

increasing the number of trips taken from Q1 to Q2, and the 

increase in WTP is estimated by the sum of areas B and C. 

5 
B 

I I 

w 

e 

P2 

Q1 Q2 

QUANTITY 

Figure 1. The demand curve and Consumer's Surplus. 

6 
w 

0 - 

a 

e 

P 

D2 

1 

Q1 Q2 

QUANTITY 

Figure 2. Effect of increased recreational "quality" on the demand 

curve and consumer's surplus. 

7 
MRF Evaluation 5/23/83 

Benefits for actions that alter the WTP through increasing the 

"quality" of the fishing experience are measured as the 

difference between the before and after WTP. This is approximated 

by the difference in areas under the before and after demand 

curves. In Figure 2 the effect of an increase in flqualityff of 

fishing is depicted as a shift in the demand curve from D1 to D2. 

Assuming that the price paid for fishing remains at P in either 

case, the value of the increased quality of fishing is 

approximated by the area labelled trOCSfl. Both Freeman(l979) and 

the Research Triangle Institute(l982) provide more extensive 

treatment and examples of these concepts. 

Because most marine recreational fishing occurs in the 

public domain, it is not possible to estimate demand curves 

directly from observed price and consumption data. These 

guidelines describe procedures for estimating the economic value 

of recreational fishing by indirect inference from travel 

behavior, participation rates and user surveys. These procedures 

will assure that evaluations are based on sound economic theory 

and have a valid empirical basis. 

!b) Criteria -- for an acceptable evaluation procedure. 

An acceptable evaluation procedure has the following 

characteristics: 

(1) The procedure should provide a reasonable 

explanation of the physical relationship between the 

action taken and the impact on marine fishing. 

(2) Evaluation should be based upon a recreational demand 

model for the particular fishery being affected or a closely 

8 
MRF Evaluation 5/23/83 

similar fishery in a different Itstudy area". 

(3) Estimates of demand should account for the socioeconomic 

characteristics of the market area populations, qualitative 

characteristics of the recreation resources under study, and 

substitutability of alternative existing recreation 

opportunities. 

(4) Evaluation should account for both the value of gains 

and losses in recreational values in the study area 

resulting from the proposed action. 

(5) Willingness to pay projections over time should be 

based upon projected changes in the underlying determinants 

of demand. 

Demand for recreational fishing trips is essentially a 

schedule of participation levels corresponding to actual or 

hypothetical prices charged for the recreation. For any given 

fishery or fishing site a demand model should predict the number 

of fishing trips (or fishing days) that would be forthcoming 

with various prices and under various conditions. 

(c> Demand Estimation Methods 

To analyze the demand for various fishing activities it is 

useful to treat the recreationist's decision as a sequence of 

choices. First, the person chooses whether or not to go saltwater 

angling. Second, the person selects the types of fishing (surf, 

beach, small boat, partyboat, pier, scuba, etc.) to participate 

in. Finally, the person must choose his preferred level of 

participation (i.e. how many trips of each type to make). Each 

stage of this decision process may be influenced by a variety of 

. 

9 
MRF Evaluation 5/23/83 

economic and environmental factors. Prominent among these factors 

are the individual's socio-economic circumstances, costs of 

participation, and the physical characteristics of the fishing 

site or type. 

Prevalence of saltwater fishing in the population at large 

represents the Stage I decision made by individuals. Thus lower 

saltwater fishing participation rates (i.e. saltwater anglers per 

1000 population) in inland areas relative to coastal areas 

reflects choices made by individuals based upon the cost of 

saltwater fishing to them, the costs and attractiveness of other 

alternative recreational opportunities, and family income levels 

(among other factors). Similarly, the proportion of saltwater 

fishing trips falling into different types presumably reflects 

choices based upon relative costs and relative attractiveness of 

the alternatives. Number of trips taken per year per angler 

(avidity) is an empirical measure of the final choice stage. 

Statistical analysis of recreational data can proceed by 

examining the probability of being a fisherman , P, the 

conditional probability of engaging in fishing type i given that 

one is a fisherman , Pi, and the number of fishing trips per year 

by fishermen engaging in type i, Ti. In symbols the relationship 

is 

TRIPS per year = Population x P xPi xTi. 

Since all three of the choice elements may be influenced by 

economic costs, economic resea.rch may focus on either the total 

demand (TRIPS) or individual sub-components. Participation models 

are sometimes used to predict prevalence of fishermen (PI or 

10 
MRF Evaluation 5/23/83 

prevalence of participants in a particular type of fishing (Pi ) 

independently of an overall demand prediction. (See Russell and 

Vaughan, 1982). 

Most recreational demand models, however, address the total 

number of trips for a particular site or type of activity. There 

are essentially three empirical approaches in current use: travel 

cost, contingent valuation (also known as "bidding games" or the 

"survey method"), and hedonic price analysis. Travel cost has the 

longest history of application to outdoor recreation (see Clawson 

and Knetsch, 1955). In its simplest form travel cost methodology 

requires only on-site sampling of participants to determine 

round-trip travel distances, trip characteristics (length, 

purpose, etc.) and ancillary socio-economic data on marine 

anglers. Given the frequency and travel costs of recreational 

trips from various distance zones, the demand curve for 

recreation at the site is estimated under the assumption that 

access costs are equivalent to a price of entry to the fishery. 

The simple travel cost study produces a demand curve showing 

recreation trips (or fishing days, depending upon whether the 

site is primarily used for day trips) as a function of simulated 

price. It will yield estimates of total consumer*s surplus 

enjoyed by recreationists at the study site and average net value 

per angler-trip. A good example of the standard travel cost model 

is W.G. Brown, A. Singh and E.N. Castle (1964). 

More sophisticated versions of the travel cost rnethodologY 

introduce multiple sites (O.R. Burt and D. Brewer, 1971), Or 

focus on values of different categories of fishing experience 

(Vaughan and Russell, 1982) or incorporate more comprehensive 

11 
MRF Evaluation 5/23/83 

multi-market models with hedonic pricing (G.M. Brown and R. 

Mendelsohn, 1981 1. All three directions of development are 

motivated by the need to estimate values for Ifenvironmental 

commodities" (e.g. clean air, freedom from encroachment of 

civilization, or different species of fish) rather than aggregate 

value of a recreation site or a recreation-day. Clearly, these 

more complicated models are pertinent to NMFSIs marine 

recreational fishing valuation objectives. 

A simplified approach to introducing fishing characteristics 

or llquality" into the demand curve was developed at the NMFS 

Economists Workshop in Orlando, Florida (November 3-5, 1982). To 

determine the incremental value of a change in species or average 

catch rate one needs to estimate the magnitude of the shift in 

the angler demand curve for fishing trips due to the change. To 

estimate such a curve requires that data be collected from a 

variety of sites which consistently offer different catch rates 

or species. Alternatively, one could examine participation at a 

given site under different fishing conditions. (See J.B. Stevens, 

1957). The typical catch rates and species types at different 

sites or times are then entered as independent variables in an 

estimated demand curve. That is, each observation at a given site 

(including number of trips per year, travel cost and socioeconomic characteristics) is augmented by the variables 

representing site characteristics. With the resulting 

!!representative fisherman's" demand for fishing trips a unit 

shift in the quality variable will cause a shift in demand curve, 

and the change in OCS is measured as the change in area under the 

12 
MRF Evaluation 5/23/83 

demand curve as depicted in Figure 2. Application of this singleequation technique is warranted where data are insufficient to 

implement a multi-equation travel cost model. 

Contingent valuation methods have been developed primarily 

for valuing public goods and for estimating values of potential 

environmental changes. In these instances, specific behavior and 

expenditure patterns are not observed. Thus, travel cost methods 

cannot be applied. A contingent valuation study requires asking 

individuals about their willingness to pay (or willingness to 

accept compensation) for different levels of the environmental 

commodity involved. There are a variety of survey formats (direct 

question, bidding game, payment card), each requiring a specific 

survey instrument and interviewing strategy. A key consideration 

in survey design is the avoidance of various sources of error and 

bias. Whether or not the sources of bias are more pernicious in 

contingent valuation than in travel cost studies is a matter of 

controversy. Readers are referred to Freeman (1 979) or Research 

Triangle Institute (1982) for a review of the methodological 

issues. 

Just as in a travel cost study, the contingent valuation 

survey must attempt to account for incremental changes in value 

due to shift variables of interest. Fish and Wildlife Service's 

National Survey of Hunting, Fishing and Wildlife Associated with 

Recreation included a battery of contingent valuation questions 

in 1975 and again in 1980. Estimates of wildlife values based 

upon the 1975 survey have been disappointing with respect to 

statistical significance of coefficients related to fish catch 

and hunters "bagr', and the resulting incremental value estimates 

13 
 

MRF Evaluation 5/23/83 

seem to be unreasonably low (G.M. Brown and J.J. Charbonneau, 

1978). Problems regarding survey design and strategy may be 

resolved in the 1980 survey. For the present, application of 

contingent valuation to marine recreational fishing is a 

permissible approach; but, it requires expert guidance from 

experienced researchers, and its results tend to raise 

controversies concerning biases and errors inherent to the 

hypothetical questioning procedures. 

Hedonic pricing models have traditionally utilized 

geographical variations in either property values or wages to 

infer IIpricesII for associated variations in environmental 

amenities. The incremental value of house or neighborhood 

characteristics derived from such models are presumably 

consistent with typical preferences, buying habits and budget 

constraints of consumers. Thus the hedonic method, like the 

travel cost method, relies more upon observed behavior than upon 

interview responses to questions. This is presumably a strong 

point. To derive demand curves for environmental commodities from 

the estimated hedonic prices and observed participation data, 

however, involves a two-stage process fraught with theoretical 

and econometric difficulties. G.M. Brown and R. Mendelsohn have 

synthesized the travel cost and hedonic models to solve a 

theoretical problem in estimating demand for characteristics from 

IIhedonic pricesf1. Their method requires that recreational 

characteristics (or qualities) vary among fishing sites and that 

recreational demand curves be estimated for several IIrnarketsII. 

Thus solution of a problem in hedonic pricing introduces the 

14 
MRF Evaluation 5/23/83 

difficulties of a multi-market analysis. For now, it is 

recommended that application of the hedonic technique await 

further development and professional consensus regarding its 

applicability and correctness. 

Selection of specific valuation methods should satisfy the 

general criteria outlined above, and the application of the 

recommended procedures should result in a written report that can 

be reviewed and referenced by "outsidetf experts. Both the travel 

cost models of recreational demand and models using "contingent 

valuation" procedures are acceptable approaches. Whenever 

possible, evaluations should use the travel cost approach or the 

more complex models developed from the travel cost approach, 

because they do not rely so heavily on interpretation of answers 

to hypothetical questions. (Rut see Schulze, et.al. or 

Rrookshire, et. al. for a more sanguine view of contingent 

valuation mechanisms.) 

IV. EVALUATION PROCEDURES 

To determine the economic benefit from a proposed action 

affecting marine recreational fishing, it is necessary to follow 

a five-step process. Table 1 lists the five steps, and the 

following paragraphs explain each step in detail. The amount of 

effort devoted to each step may vary from one application to 

another, depending upon the nature of the proposed action, the 

difficulty of establishing the physical linkage between the 

action and the recreational experience, and the sensitivity of 

the evaluation to the formulation of the demand model. In every 

15 
MRF Evaluation 5/23/83 

case, however, the procedure seeks to determine the condition of 

the fishery without the action, the probable effect of the action 

on the fishery, and effect that the action has on the demand for 

recreational fishing. The net economic value is then reckoned as 

the change in economic benefit occurring in the defined fishery 

due to the proposed action. 

Step 1. Define the Affected Fishery _c_- 

Changes in recreational activity due to proposed actions 

will typically be concentrated in some geographical or "marketff 

area. The impacts should be related to (1) actual and potential 

recreationists drawn from identified locations and ('2) a 

particular set of fishing locations, species, stocks and/or modes 

of fishing. Description of the subject fisheries and an inventory 

of biological resources involved should be included in this first 

step. Also needed is a definition of particularly important 

fishing sites, description of the qualities of recreational 

fishing alternatives available, and an explanation of significant 

constraints to ocean access, if any. Reference to statistical 

evidence regarding volume of recreational activities (e.g. angler 

days by mode of fishing) and spatial distribution of subject 

angling population is encouraged. 

-- Step 2. Determine How Physical Conditions Affect Recreational 

"Quality" and Quantity. 

Fishery management and development actions often cause 

physical changes not directly experienced by marine recreational 

16 
R 

MRF Evaluation 5/23/83 

fishermen. And many of these physical changes will directly or 

indirectly impact important characteristics or Itqualitytl factors 

without directly augmenting or diminishing the potential quantity 

of recreational opportunities. For example, the average size, 

species composition or number of fish available within a region 

may be altered. The effect of these on fishing characteristics 

important to anglers should be assessed. That is, linkages 

between objective conditions in the biological realm and 

perceived recreational tlqualitylt need to be established. 

A change in catch per angler day is one useful measure of 

recreational tlquality*t. Other measures developed should be 

justified by reference to source data, existing published 

studies, etc. Quantitative relationships between the important 

physical conditions (like fish stock size) and recreational 

quality components (like angler catch rate) may be derived from 

statistical models for the subject fishery or from studies of 

closely similar fisheries. Or a hypothesized relationship may be 

developed from accepted theory with specific adaptation to the 

subject fishery. 

As an example of the latter approach, suppose population 

biologists determine that the angler catch rates are proportional 

to fish stock abundance. A particular fishery project is expected 

to increase the stock by 10 percent. The observable consequence 

for the angler would be a 10 percent increase in catch per day of 

fishing. The pertinent issue for the economic valuation exercise 

is whether the value of recreational fishing is significantly 

enhanced by the higher catch prospects. 

17 
MRF Evaluation 5/23/83 

-- STEP 3. Estimate Baseline Recreational Activity and Value 

of Recreational Fishing. 

This step attempts to establish a base condition from which 

the proposed action will cause changes. The base condition may or 

may not be equivalent to recent past conditions. If some recent 

shift in the physical or economic setting has occurred, or a 

trend can be reliably extrapolated, the base condition could be 

established by predicting the near future. Whatever procedure is 

used, this base condition must include (1) an estimate of the 

number and types or recreational fishing trips that will occur in 

the subject fishery, and (2) the net economic value (WTP,WTA or 

OCS) aggregated for the whole fishery. Both components may be 

derived from a comprehensive model of demand for recreational 

fishing. Or the two components might be developed from separate, 

but consistent, empirical models. 

(1 Estimating Volume of Recreational Activity. 

If no change from recent socioeconomic and institutional 

conditions are expected to occur in the absence of the proposed 

action, the estimated level of recreational fishing may be equal 

to recent historical levels. This is the simplest approach. On 

the other hand, a better prediction may be derived from a model 

which accounts for differing recreational participation rates 

across travel distance zones and socioeconomic strata. Given per 

capita participation (e.g. fishing trips per year per angler) by 

residence zone and socioeconomic strata of anglers, future 

participation can be extrapolated based on population growth and 

other trends. To implement an extrapolation such as this requires 

extensive survey information revealing the geographic 

18 
4 

MRF Evaluation 5/23/83 

distribution and socioeconomic characteristics of marine 

recreational fishermen. Data collected for a travel cost study 

may provide the necessary information. 

A more sophisticated analysis might account for the effects 

of anticipated trends in recreational fishing conditions or 

fishing quality. For example, an established trend in fish 

availability, ocean access, or cost of participation (e.g. 

increasing cost of travel) may be expected to have an important 

influence upon future participation in fishing independently of 

general demographic trends. To account for these kinds of effects 

in the base condition requires a quantitative nodel linking 

recreational participation to the qualities or characteristics 

that are expected to be trending. 

Such a linkage may be developed as part of a recreational 

fishing demand model, wherein the changing characteristics are 

represented as 'Ishift'I variables in the demand curve. Travel cost 

demand studies may introduce these shift variables when multiple 

sites are surveyed and fishing characteristics vary among sites. 

For example, the per capita demand (expressed as number of 

fishing days or trips per year) for a particular fishery may be 

expressed as a function of travel distance, catch per angler day, 

and other socioeconomic factors. The equation must be estimated 

using a data set that includes trips from a variety of distance 

zones to a cross-section of fishing sites offering a variety of 

catch opportunities. The effect of changing the typical catch 

rate at a given site or group of sites can then be computed by 

extrapolating the per capita change in fishing trips across the 

entire population from which marine anglers are drawn. This is 

19 
MRF Evaluation 5/23/83 

essentially a matter of multiplying the change in trip frequency 

at each distance and in each socioeconomic strata by the number 

of people in each such strata. 

(2) Estimating Value of Recreational Fishery. 

As in the previous section, the baseline economic value can 

be either an estimate of value in the recent past (i.e. the 

present condition) or an estimate of future value based upon a 

quantitative model of changing conditions and changing 

recreational demand. In either case the basic notion of economic 

value is the WTP, WTA, or OCS concept discussed in Section I11 

above. The recommended procedure is to estimate value per 

recreational fishing day or trip based upon a percapita 

recreational demand equation. Demand equations can be developed 

using any of the suggested models described in the References. A 

simple travel cost recreational demand model will support - an 

estimate of net economic value (ordinary consumer's surplus) per 

fishing day or fishing trip. This value will vary with distance 

travelled, so that the aggregate economic value must be computed 

by weighting the value per day in each distance zone by the 

population of anglers in each distance zone. 

Similarly, a Contingent Valuation Mechanism may be used to 

develop a percapita WTP for recreational fishing in the base 

condition. Here one must be careful to get a per capita value per 

unit of recreation and to provide the ancillary information 

necessary to relate the WTP to socioeconomic and demographic 

variables. Again, an aggregate value should be calculated based 

upon weighting the percapita values associated with different 

20 
MRF Evaluation 5/23/83 

socioeconomic and demographic strata by the size of population 

occurring in those strata. 

- STEP .- 4 Estimate Changes in Recreational Activity and Economic 

Value. 

This step should be a simple matter of combining results 

from Step 2, concerning mechanisms by which proposed actions 

affect recreational fishing, with those of Step 3, developing the 

economic model of recreational demand that incorporates the 

relevant "shiftf1 variables. Per capita participation ("demandf1) 

in the subject fishery will rise or fall, and the value per day 

or trip may change due to the proposed action. The relative size 

and importance of these two components will vary markedly from 

case to case. 

An example is the case of improved fish availability in a 

specific fishery. The analysis in Step 4 should indicate the 

level of participation (demand) and WTP (or OCS) per angler as of 

the baseline condition. Furthermore, it is necessary that the 

analysis focus on the effects of fish availability (possibly 

measured as catch per angler-day) on the demand curve. If the 

underlying methodology is a travel-cost model, this might be 

accomplished by developing !he model from a cross-section of 

fishing sites having different catch rates (see C.S. Russell and 

W.J. Vaughan, 1982), or from a time series on participation and 

angling success (see J.B. Stevens). In a contingent valuation 

approach, interviewees would be presented with alternative 

21 
MRF Evaluation 5/23/83 

fishing conditions. In either case, the change in recreational 

value per angler is estimated by the change in area (positive or 

negative) under the demand curve. 

Since the estimated demand curve pertains to a 

representative angler facing specific conditions and alternatives 

(including travel distance), computation of the aggregate change 

in economic value may be fairly complicated. For instance, in a 

travel-cost framework, the change in consumer's surplus per 

angler will vary across distance zones. Thus the aggregate change 

in value equals the sum of the changes in each zone; and the 

change in each zone equals the change in value per representative 

angler times number of anglers. 

The proposed project or regulatory action may cause a 

complex change in fishing qualities, as when availability of some 

species is affected by the stock of another species. Or, a 

project might increase the amount of reef-related fishing while 

decreasing the opportunities for or aesthetic quality of troll 

fishing. In these cases, the analyst must make an effort to 

estimate the negative effects as well as the positive effects. 

This may require that demand models be developed for more than 

one fishery. 

22 
MRF Evaluation 5/23/83 

_IIStep 5. Display Gains and Losses I__ 

To promote understanding by non-economists and to facilitate 

access by economists it is recommended that a summary display be 

attached to any report on recreational evaluation. The following 

items should be included in the display: 

(1) Definition of Fishery or Fisheries Impacted. 

*Location (major sites, States, etc.) 

*Species of fish involved. 

"Typical number of participants broken down by mode 

fishing. 

(2) Short Statement of Proposed Action 

(3) Predicted physical effects on recreational quality, 

accessibility, etc. (i.e. what change in catch rate, 

species mix, or quantity of fishing grounds is 

expected) 

(4) Quantitative summary of positive and negative impacts, 

including estimated changes in participation and value 

per angler day. 

(5) Aggregate net impact of proposed action on recreational 

fishing value. 

This final display should take the form of a one-to-two page 

Table or Figure. 

To illustrate, a summary display (Table 2) has been created 

from information reported by Cliff Russell and William Vaughan in 

their assessment of the recreational fishing benefits from the 

Federal Water Pollution Control Act. They use existing 

biophysical models to predict increased acreage of suitable water 

habitat, and develop participation models to predict the effects 

of increased fishable water on levels of recreational fishing. 

Increased aggregate value of recreation is related to increased 

participation in freshwater angling by applying ?'willingness to 

pay" estimates generated from an independent study of fee fishing 

23 
MRF Evaluation 5/23/83 

sites. No losses are shown here because all recreational impacts 

are predicted to be positive overall. Underlying the aggregate 

gain, however, is a predicted shift of relative proportions of 

fishing categorized as "rough'? (e.g. carp, catfish) and 

"gamefishft. A full cost-benefit analysis would, of course, 

include estimated capital and operating costs associated with the 

"best practicable technology" used to meet the clean water 

standards. 

An approach such as that demonstrated by Russell and Vaughan 

could be profitably applied to marine recreational fishing. The 

summary Table 2 illustrates some useful points regarding 

application of economic analysis to recreational value questions. 

First, impacts of policy changes affect aggregate recreational 

value through its affects on (1) number of people that choose to 

participate in the activity at any level, (2) the level of 

participation by active anglers in various modes of fishing, and 

(3) the "willingness to pay", or "recreational day value" 

pertaining to different modes of fishing. In the Russell and 

Vaughan study, the predicted change in number of anglers was very 

small while the predicted increase in number angler fishing-days 

was somewhat larger. The economic value per day of fishing was 

assumed constant regardless of the amount of acreage of habitat 

or level of participation. 

Second, the authors acknowledge the lack of agreement in the 

economics profession on how to incorporate the value of time in a 

travel-cost model and the uncertainty on whether fees at fishing 

sites represent pure land rents or compensation for real costs. 

This results in a vrlowtt and a rrhigh" estimate of value per 

24 
MRF Evaluation 5/23/83 

recreation day. Since the resulting aggregate value estimates 

range from $319 million to $683 million, this gap in knowledge 

may leave an indeterminacy in any cost-benefit analysis utilizing 

this valuation study. But this is a fair and honest presentation, 

and there is no necessity for the study to pretend to greater 

precision than can actually be achieved. 

V. DATA AVAILABILITY 

Three major surveys have been conducted in recent years that 

obtained economic data elements on a national scale: (1) the 

ongoing NMFS Marine Recreational Fishery Statistics Survey 

(MRFSS), (2) the 1981 NMFS Socioeconomic Survey (S/E Survey) and 

(3) the 1980 U.S. Fish and Wildlife's National Survey of Fishing 

and Hunting. The MRFSS program fielded the first of a series of 

new surveys in 1979 with the objective of obtaining catch, effort 

participation data at the Regional Council level of detail. 

In addition to catch data, travel cost data elements were 

obtained during 1979 and 1980. Table 3 lists the types of data 

collected by the MRFSS. During 1981 the S/E survey covered a 

broader range of socioeconomic data elements. These are described 

in Table 4. 

Both the MRFSS and S/E Survey are based on a combination of 

intercept and telephone contacts. The MRFSS survey is structured 

so that detailed catch, species, fishing mode and location 

information is collected at the fishing site through intercept 

interviews. A separate telephone survey, which provides a canvass 

25 
MRF Evaluation 5/23/83 

of the general population in coastal areas, collects data 

pertaining to level of fishing activity by mode of fishing and 

residence location. During 1979 and 1980 the economic data on 

travel cost were collected during the intercept surveys. During 

1981 the S/E Survey utilized both intercept and telephone followups. That is, an angler contacted at the fishing site was also 

telephoned later with additional questions concerning 

expenditures, satisfaction level, disposition of catch, 

employment status and income. For analytical purposes, data from 

either of the NMFS surveys must be weighted by the proportion of 

the total saltwater fishing population falling into the pertinent 

region/mode. These weights are computed from the MRFSS telephone 

survey information. 

U.S. Fish and Wildlife Service's National Survey of Fishing 

and Hunting (NSFH) collects annual information concerning 

saltwater angling activities. Table 5 lists the types of data 

collected. Major differences between this survey and the NMFS 

surveys are: 

(1) The NSFH surveys occur at five year intervals rather 

than annually; 

(2) The NSFH canvasses the U.S. population by telephone and 

conducts personnel interviews with a subsample in order to 

obtain statistically reliable results at the State level. 

The MRFSS canvasses the population only in a "coastal strip" 

and collects detailed species information by on-site 

intercept. 

26 
MRF Evaluation 5/23/83 

(3) The NSFH asks anglers to recall the previous year's 

experience, while the MRFSS is conducted at two-month 

intervals. 

None of the data from these surveys is ideal for economic 

evaluation, but they should provide a first line of attack for 

specific recreational evaluation studies. At the very least, the 

general nationwide data can provide the analyst with an 

appreciation for the total numbers likely to be involved in 

marine fishing, broken down by region and mode of fishing. For 

some widespread fisheries, the MRFSS plus S/E survey may provide 

sufficient coverage and sample size to conduct an economic 

evaluation. In other cases, an examination of the available data 

will assist the development of a more in-depth local survey. 

Further information on the NMFS surveys is available from 

Dr. Mark Holliday, NMFS F/SR1, 3300 Whitehaven St. N.W., 

Washington D.C. 20235. For more information on the National 

Survey of Fishing and Hunting contact Dr. M.J. Hay, U.S. Fish and 

Wildlife Service, Room 2556, Dept. of Interior, 18th and C 

Streets N.W., Washington, D. C. 20240. 

27 
MRF Evaluation 5/23/83 

Table 1. Recommended Steps in Economic Evaluation Procedure. 

1. Define the Affected Fishery 

2. Determine How Physical Conditions Affect 

Recreational "Qualityf1 or Quantity 

3. Estimate Baseline Recreational Activity 

and Economic Value. 

4. Estimate Changes in Recreational Activity and' 

Economic Value. 

5. Display the Gains and Losses in Economic Value 

28 
c 

MRF Evaluation 5/23/83 

Table 2. Example of Fishery Value Impact Display. (Derived 

from C.S. Russell and W.J. Vaughan, 1982b) 

I. IDENTIFICATION OF FISHERY IMPACTED: 

* All U.S. freshwater recreational fishing 

* Baseline Participation Levels 

Pre-cleanup fishable waters in U.S. - 30,615,000 acres 

Pre-cleanup U.S. freshwater anglers - 59,160,000 

Pre-cleanup distribution of angling activities: 

Co 1 dwa t er gam e f i sh 20.4% 

Wa rmwa t er g amef ish 68.4% 

"Roughff fishing 11.2% 

11. PROPOSED ACTION: Improve Water Quality to be consistent with 

"Best Practicable Technology" as required under the 1972 

Amendments to the Federal Water Pollution Control Act. 

111. PREDICTED PHYSICAL EFFECTS: 

Increased amount of water fit for gamefish and fish, 

and increased total amount of fishable water to 3O,721,000 acres. 

After water is improved and fish adjust to new water habitat, the 

proportions of fishing in different categories is estimated to 

be: 

Co 1 d wa t er g am e fish 22.7% 

Warmwater gamefish 73.6% 

Rough fish 3.7% 

29 
MRF Evaluation 5/23/83 

TABLE 2. Continued 

IV. GAINS AND LOSSES DUE TO WATER POLLUTION CONTROL (BPT) 

Quanti tat ive Measur e Before After Change 

Number of Anglers (millions) 59.16 59.18 0.02 

Days of fishing per year 

(mill ions) 

- Co 1 d wa t er gam e f i s h 301.8 319.3 17.5 

-Warmwater gamef ish 737.4 741.4 4.0 

-Rough fish 209.8 220.8 11.0 

Recreational Value per Year 

($mill ions) 

-Low Es t imat e* 11,962.5 12,281.4 318.9 

-High Estimate 26,410.5 27,093.8 683.4 

* Estimated values per day for fishing are: 

Co 1 dwa ter g ame fishing 

Warm wa t er g am e f i s h ing 

Rough Fishing 

Low High 

$11.1 $24.1 

$ 9.7 $21.4 

$ 7.0 $16.0 

The low estimates do not include value of travel time in the dayvalue model, and they assume fees paid at site represent real 

costs. High estimates include travel time valued at average wage 

rates and assume entry fees are pure transfers. 

30 
L c 

MRF Evaluation 5/23/83 

TABLE 3. DATA ELEMENTS FROM MRFS SURVEY 

1. Fishing location and Mode (pier, jetty, beach, boat,etc.) 

2. Activity level 

a. hours fishing on day of intercept interview 

b. number of fishing trips taken in past 2 months and 

past year 

3, "Economic data" (not collected after 1980) 

a. miles traveled to fishing site 

b. expenses for fishing trip (bait, ice, clothing, food 

sundries, lodging, etc.) 

4. Demographic data (sex, language, age, county of 

residence) 

5. Fish catch by species and disposition. 

31 
MRF Evaluation 5/23/83 

TABLE 4. DATA ELEMENTS FROM S/E SURVEY, 1981 

1. Age, sex, Catch(Identica1 to MRFSS) and household size 

2. Distance traveled 

3. Complete trip expenditures for 

- boat rental - lodging 

- food - fuel 

- sundries - bait 

-processing catch - misc. equipment 

-tackle -tolls/ parki ng 

-feedlicenses 

4. 1980 pre-tax income and employment status at time of 

t el ephone inter v i ew . 

5. motivational categories and years of saltwater fishing 

experience. 

6. Level of satisfaction (ranked 1 - 4) and reasons. 

32 
MRF Evaluation 5/23/83 

TABLE 5. DATA ELEMENTS IN SALTWATER FISHING PORTION OF U.S. FISH 

AND WILDLIFE SERVICE'S NATIONAL SURVEY OF FISHING AND 

HUNTING. 

1. Regions in which interviewee fished 

2. Number of trips to each region during previous year 

3. Number and kinds of days fished 

4. Days fished and average number of fish caught per day by 

regions for shad, salmon, steelhead, striped bass. 

5. One-way travel distance to "usual11 place of fishing 

6. Fishing trip expenditures (food, transportation, lodging, 

fees, equipment rental) 

7. 1980 fishing equipment expenditures separated into 

freshwater and saltwater 

33 
MRF Evaluation 5/23/83 

REFERENCES 

N.E. Bockstael and K. E. McConnell. 1980. Calculating equivalent 

and compensating variation for natural resource 

environments. Land Economics, Vol. 56(1 ):56-63. 

D.S. Brookshire, M.A. Thayer, W.D. Schulze, and R.C. d'Arge. 1982. 

Valuing public goods; a comparison of survey and hedonic 

approaches. Amer. Econ. Rev. 72(1):165-177. 

G.M. Brown, Jr. and J.J. Charbonneau. 1978. Estimating values of 

wildlife: analysis of the 1975 Hunting and Fishing Survey. 

Working Paper No. 7, Div. of Program Plans, U.S. Fish and 

Wildlife Service. 

and R. Mendelsohn. 1981. Hedonic demand functions with 

linear and non-linear budget constraints. Unpub. ms. 

University of Washington, Seattle. 

W.G.Brown, A. Singh and E.N. Castle. 1964. An economic evaluation 

of Oregon salmon and steelhead sport fishery. Ore Agric. 

Exp. Sta. Bul. 78. Corvallis. 

O.R. Burt and D. Brewer. 1971. Estimation of net social benefits 

from outdoor recreation. Econometrica 39(Sept. 1 : 81 3-27. 

F.J. Cesario. 1976. Value of time in recreation benefit studies. 

Land Economics 52 (1 : 32-4 1. 

M.Clawson and J.L. Knetsch. 1966. Economics - of outdoor 

recreation. Bal t imore :The Johns Hopki ns Un iv er si t y 

Press/Resources for the Future. 

T.A. Deyak and V.K. Smith.1978. Congestion and participation in 

outdoor recreation: a household production function 

approach. J. Environmental Econ. and Manage. 5:65-80. 

J.F.Dwyer, J.R.Kelly and M.D. Bowes. 1977. Improved procedures 

for valuation of the contribution of recreation to national 

economic development. Univ. of Illinois at Urbana-Champaign, 

Water Resources Center, Res. Rep. No. 128. 

A.M.Freeman, III.1979.The 7 Benefits of Environmental Improvenent: 

Theory and Practice.Baltimore7 Johns Hopkins University 

Press/Re=rces for the Future. 

P.A.Meyer. 1979. Publicly vested values for fish and wildlife: 

criteria in economic welfare and interface with the law. 

Land Economics, 55(2):223-235. 

Research Triangle Institute. 1982. (Draft) Benefit-cost assessment 

handbook for water programs. Vol. 1.Prepared for U.S. 

Environmental Protection Agency, Office of Policy Analysis. 

34 
MRF Evaluation 5/23/83 

C.S. Russell and W. J. Vaughan. 1982. National recreational fishing 

benefits of water pollution control. J. Environmental Econ. 

and Manag. 9(4 1: 328-354. 

J.B.Stevens. 1966. Recreation benefits from water pollution 

control. Water Resources Research; 2(2): 167-182. 

U.D.Schulze, R.C. d'llrge and D.S.Brookshi~-e. 1981. Valuing 

environmental commodities: some recent, experience. Land 

Economics 5?(2): 151-172. 

W.J. Vaughan and Clifford S. Russell. 1982. Valuing a fishing 

day: an application of a systematic varying parameter model. 

Land Economics 58(4):450-461. 

Water Resources Council. 1979. Net economic development benefit 

evaluation procedures: recreation. Federal Register 44(242): 

72950-72965. 

R.D.Willig. 1976. Consumer's surplus without apology. Amer. Econ. 

Rev. 66(4):589-5?7. 
a 

MRF Evaluation 5/23/83 

Table 2. Example of Fishery Value Impact Display. (Derived 

from C.S. Russell and W.J. Vaughan, 1982b) 

I. IDENTIFICATION OF FISHERY IMPACTED: 

* All U.S. freshwater recreational fishing 

* Baseline Participation Levels 

Pre-cleanup fishable waters in U.S. - 30,615,000 acres 

Pre-cleanup U.S. freshwater anglers - 59,160,000 

Pre-cleanup distribution of angling activities: 

Coldwa t er game f ish 20.4% 

Wa rm wa t e r g am e f i s h 68.4% 

u Ro ug h" f i s h i n g 11.2% 

11. PROPOSED ACTION: Improve Water Quality to be consistent with 

"Best Practicable Technology" as required under the 1972 

Amendments to the Federal Water Pollution Control Act. 

111. PREDICTED PHYSICAL EFFECTS: 

Increased amount of water fit for gamefish and "roughv1 fish, 

and increased total amount of fishable water to 3O,721,000 acres. 

After water is improved and fish adjust to new water habitat, the 

proportions of fishing in different categories is estimated to 

be : 

Coldwa t er game f ish 22.7% 

Warm wa t e r g am e f i s h 73.6% 

Rough fish 3.7% 

29 

._ 
MRF Evaluation 5/23/83 

TABLE 2. Continued 

IV. GAINS AND LOSSES DUE TO WATER POLLUTION CONTROL (BPT) 

Quanti t at iv e Me a sur e Before After Change 

Number of Anglers (millions) 59.16 59.18 0.02 

Days of fishing per year 

(mill ions) 

-Co ldwa t er gam e f ish 301.8 319.3 17.5 

-Warm wa t e r g am e f i s h 737.4 741.4 4.0 

-Rough fish 209.8 220.8 11.0 

Recreational Value per Year 

($millions) 

-Low Estimate* 11,962.5 12,281.4 318.9 

-High Estimate 26,410.5 27 , 093.8 683.4 

* Estimated values per day for fishing are: 

Low High 

Co 1 d wa t e r g am e f i s h i ng $11.1 $24.1 

Rough Fishing .g 7.0 $16.0 

Warmwa ter game fishing $ 9.7 $21.4 

The low estimates do not include value of travel time in the dayvalue model, and they assume fees paid at site represent real 

costs. High estimates include travel time valued at average wage 

rates and assume entry fees are pure transfers. 
L e 

MRF Evaluation 5/23/83 

TABLE 3. DATA ELEMENTS FROM MRFS SURVEY 

1. Fishing location and Mode (pier, jetty, beach, boat,etc.) 

2. Activity level 

a. hours fishing on day of intercept interview 

b. number of fishing trips taken in past 2 months and 

past year 

3. lfEconomic data" (not collected after 1980) 

a. miles traveled to fishing site 

b. expenses for fishing trip (bait, ice, clothing, food 

sundries, lodging, etc.) 

4. Demographic data (sex, language, age, county of 

residence) 

5. Fish catch by species and disposition. 

31 
MRF Evaluation 5/23/83 

TABLE 4. DATA ELEMENTS FROM S/E SURVEY, 1981 

1. Age, sex, Catch(Identica1 to MRFSS) and household size 

2. Distance traveled 

3. Complete trip expenditures for 

- boat rental - lodging 

- food - fuel 

-sundries - bait 

-processing catch - misc. equipment 

-tackle 

-feedlicenses 

- to 11 s/ parki ng 

4. 1980 pre-tax income and employment status at time of 

telephone interview. 

5. motivational categories and years of saltwater fishing 

experience. 

6. Level of satisfaction (ranked 1 - 4) and reasons. 

32 
MRF Evaluation 5/23/83 

TABLE 5. DATA ELEMENTS IN SALTWATER FISHING PORTION OF U.S. FISH 

AND WILDLIFE SERVICE'S NATIONAL SURVEY OF FISHING AND 

HUNTING. 

1. Regions in which interviewee fished 

2. Number of trips to each region during previous year 

3. Number and kinds of days fished 

4. Days fished and average number of fish caught per day by 

regions for shad, salmon, steelhead, striped bass. 

5. One-way travel distance to t'usual" place of fishing 

6. Fishing trip expenditures (food, transportation, lodging, 

fees, equipment rental) 

7. 1980 fishing equipment expenditures separated into 

freshwater and saltwater 

33 
MRF Evaluation 5/23/83 

REFERENCES 

N.E. Bockstael and K.E. McConnell. 1980. Calculating equivalent and compensating variation for natural resource 

environments. Land Economics, Vol. 56(1 ):56-63. 

D.S. Brookshire, M.A. Thayer, W.D. Schulze, and R.C. d'Arge. 1982. 

Valuing public goods; a comparison of survey and hedonic 

approaches. Amer. Econ. Rev. 72(1):165-177. 

G.M. Brown, Jr. and J.J. Charbonneau. 1978. Estimating values of 

wildlife: analysis of the 1975 Hunting and Fishing Survey. 

Working Paper No. 7, Div. of Program Plans, U.S. Fish and 

Wildlife Service. 

and R. Mendelsohn. 1981. Hedonic demand functions with 

linear and non-linear budget constraints. Unpub. ms. 

University of Washington, Seattle. 

W.G.Brown, A. Singh and E.N. Castle. 1964. An economic evaluation 

of Oregon salmon and steelhead sport fishery. Ore Agric. 

Exp. Sta. Bul. 78. Corvallis. 

O.R. Burt and D. Brewer. 1971. Estimation of net social benefits 

from outdoor recreation. Econometrica 39(Sept.) : 81 3-27. 

F.J. Cesario. 1976. Value of time in recreation benefit studies. 

Land Economics 520 1 : 32-4 1. 

M.Clawson and J.L. Knetsch. 1966. Economics - of outdoor 

recreation. Ba1timore:The Johns Hopkins Un iv er si ty . -~ -~ ~~ 

Press/Resources for the Future. 

T.A. Deyak and V.K. Smith.1978. Congestion and participation in 

outdoor recreation: a household production function 

approach. J. Environmental Econ. and Manage. 5:65-80. 

J.F.Dwyer, J. R.Kelly and M.D. Bowes. 1977. Improved procedures 

for valuation of the contribution of recreation to national 

economic development. Univ. of Illinois at Urbana-Champaign, 

Water Resources Center, Res. Rep. No. 128. 

A.M.Freeman, IIT.1979.The - Benefits of Environmental Improvenent: 

Theory and Practice.Baltimore7 Johns Hopkins University 

Press/Re%rces for the Future. 

P.A.Meyer. 1979. Publicly vested values for fish and wildlife: 

criteria in economic welfare and interface with the law. 

Land Economics, 5542) : 223-235. 

Research Triangle Institute. 1982. (Draft) Benefit-cost assessment 

handbook for water programs. Vol. 1.Prepared for U.S. 

Environmental Protection Agency, Office of Policy Analysis. 

34 
MRF Evaluation 5/23/83 

C.S. Russell and W.J. Vaughan. 1982. National recreational fishing 

benefits of water pollution control. J. Environmental Econ. 

and Manag. 9(4 1 : 328-354. 

J.B.Stevens. 1966. Recreation benefits from water pollution 

control. Water Resources Research; 2(2): 167-182. 

W.D.Schulze, R.C. d' Arge and D. S.Brookshire. 1981. Valuing 

environmental commodities: some recent, experience. Land 

Economics 57(2): 151-172. 

W.J. Vaughan and Clifford S. Russell. 1982. Valuing a fishing 

day: an application of a systematic varying parameter model. 

Land Economics 58(4):450-461. 

Water Resources Council. 1979. Net economic development benefit 

evaluation procedures: recreation. Federal Register 44(242): 

72950-72965. 

R.D.Willig. 1976. Consumer's surplus without apology. Amer. Econ. 

Rev. 66(4): 589-597. 

35