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Assessing the validity of contingent valuation: Three field experiments
The Science of the Total Environment, 56 (1986) 99--107 Elsevier Science Publishers B.V., Amsterdam -- Printed in The Netherlands
99
ASSESSING THE VALIDITY OF CONTINGENTVALUATION: THREEFIELD EXPERIMENTS* T. A. HEBERLEINl and R. C. BISHOP2 l Department of Rural Sociology, University of Wisconsin, Madison, Wisconsin, USA 2 Department of Agricultural Economics, University of Wisconsin, Madison, Wisconsin, USA
ABSTRACT Contingent valuation, in social psychological terms, is a measure of behavioral intention (BI), or what people say they w i l l do on surveys. Market values, on the other hand, are obtained through observable buying and selling behaviors (B). The relationship between BI and B was explored in three f i e l d experiments. Hunters had an opportunity to sell t h e i r free but d i f f i c u l t to obtain hunting permits or buy such a permit. When i t came to selling permits in a take I t or leave i t situation, the amount people sald they would take was 60 percent higher in one experiment and 200 percent higher in the other than what they actually sold i t for. Willingness to sell values were greatly inflated by using a sealed bid auction, and In this case hunters said they would take less than they r e a l l y would take. For selling we conclude contingent valuation is not a good substitute for market behaviors. In contrast, willingness to pay is a much better indicator of what hunters actually pald to buy a permit. In two experiments, BI was 25 percent and 33 percent higher than B (N.S.). Further, the sealed bld auction gave the same results as dichotomous choice. Bidding in the willingness to pay situation increased the difference between BI and B. We speculated that because of repeated buying behaviors consumers have a pretty good idea of what they w i l l ~ay and can answer correctly on a survey. In contrast they seldom sell things, especially hunting permits, and do not have a good idea of what they r e a l l y w i l l sell for until confronted with cash. INTRODUCTION To obtain d o l l a r values for environmental goods which are not usually bought and sold in a market, economists have turned to survey research.
A
hypothetical market is set up where a respondent is asked in a survey the maximum amount he or she would pay for clean a i r or water or the minimum
*This research was supported by the College of A g r i c u l t u r e and L i f e Sciences, U n i v e r s i t y of Wisconsin, Madison, Resources f o r the Future I n c . , The Electrtc Power Research I n s t i t u t e , and the W i l d l i f e Management I n s t i t u t e . Thanks are due to our various research assistants Robert M. Baumgartner, Mary Jo Kealy, Michael P. Welsh and to the Wisconsin Department of Natural Resources p a r t i c u l a r l y Joseph C. Haug, Kent E. Kleptnger, John N. Kubtstak, and Ned Norton.
0048-9697/86/$03.50
© 1986 Elsevier Science Publishers B.V.
100
amount he or she would take in return for accepting some lower standard of environmental quality.
These responses to questionnaires are referred to as
contingent values since the d o l l a r values obtained are the amounts individuals say they are w i l l i n g to pay or receive contingent on the creation of a market. In cost-benefit analysis these contingent values are compared with market values of commodities which normally are bought and sold.
Contingent
valuation represents a real step forward in measuring environmental values and integrating these nonmarket values into decisions about the environment. The question remains, however, are the values people give in response to a survey really what they would pay or take in a real market with real dollars?
In
posing this question, economists have raised some fundamental social psychological issues.
In this paper we examine contingent valuation from this
view point and present experimental evidence on the v a l i d i t y of contingent valuation. CONTINGENT VALUATION: A SOCIAL PSYCHOLOGICAL PERSPECTIVE In social psychological terms, contingent values are behavioral intentions, not actions.
A behavioral intention is an unobservable psychological state
which must be inferred from questionnaire responses. A behavioral intention is one of the three t r a d i t i o n a l components of the attitude concept (McGuire, lg69; Rokeach, 1969; Fishbein, 1967). Liking or d i s l i k i n g (affect) and beliefs (cognition) are the other two components. Becausei t is a psychological variable, behavioral intentions may change with some rapidity. In contrast, a behavior is d i r e c t l y observable and once engaged in is a historical fact. The values obtained through a market process reflect results of many behaviors in the i n s t i t u t i o n a l context of a market, while contingent values a single intention to a hypothetical situation.
There exists in social
psychology a considerable debate about the relationship between behavioral intention and behavior.
Fishbein (1967, p. 48B) argues that in some cases
" . . . t h e correlation betweenmeasures of behavioral intention and the actual overt behavior is almost perfect."
Using prisoner dilemma games in laboratory
situations Ajzen and Fishbein found very high correlations between behavioral intentions and behaviors [ r = .B9 (Ajzen and Fishbein, 1970) r = .82 (Ajzen, IgTl)] and concluded that "...accurate behavioral prediction is possible when appropriate measures of behavioral intentions are obtained" (Ajzen and Fishbein, 1973, p. 49).
Fromthese studies one might conclude that contingent
values would be good surrogates for actual behavior and that CV measures from surveys could be d i r e c t l y and v a l i d l y compared with economic values obtained from behaviors in the market place.
I01 These high correlations between behavioral intentions (BI) and behavior (B) have, however, occurred in highly controlled situations where subjects had only two choices and were asked, after engaging in behaviors for a number of t r i a l s , how they intended to behave in the next series of t r i a l s . these cases we would expect the highest BI-B relationship.
I t is in
As Ajzen and
Fishbein (IgTO, p. 485) point out "a one to one relationship is expected i f , and only i f , BI is very specific to B and is measured immediately preceding the performance of B."
They also state (p. 4B6) that " . . . i t must be made
clear that an intention is only an intention, and in many cases, i t may not be possible for an individual to carry through his (sic) intentions because of various kinds of situational or interpersonal constraints.
While problems of
this kind can be avoided in the laboratory, i t may be necessary to consider them in f i e l d situations." Sociologists who are concerned with actual behavior in f i e l d settings have been more skeptical about the BI-B relationship.
Reviewing the sociological
l i t e r a t u r e beyond the laboratory Schuman and Johnson (1976) argue that a measured attitude is not a substitute for behavior.
The seminal and most
widely quoted study of the BI-B relation involved actual economic choices (La Piere, 1934). During the depression years of 1930-1932, hotels and restaurants a l l over the United States were surveyed by La Piere and said that they would not accept guests of a certain minority race (Chinese).
Whenthey
were confronted with Chinese guests who looked as i f they could pay, however, almost a l l did admit them as guests. Thus the observed behavior in this market transaction was dramatically different than the behavior intention. The point here is simply as Fishbein and Ajzen (1976, p. 580) argue " . . . t h e empirical relation between intention and behavior cannot be taken for granted but must be submitted to systematic empirical investigation." In this paper we are reporting the results of three f i e l d experiments where behavioral intentions (contingent values) as measures of behavior involving real money are obtained.
The f i r s t experiment involves the willingness to sell a goose
hunting permit, while the second two the willingness to sell or buy a deer hunting permit. THREE EXPERIMENTS Experiment I involved permits which authorized the bearer to take at most one Canada goose between October l and October 15, 1978 in an area around the 24,600 acre Horizon Marsh in central Wisconsin.
A hunter could legally
receive only one such permit, and a total of 13,g74 were issued by the Wisconsin Department of Natural Resources. The permits were free, but over 50,000 hunters apply for them.
102
A random sample was drawn of 237 hunters who had been issued a permit. Each received an actual cash offer to give up the permit.
Cash offers were
randomly determined ranging in roughly log-linear intervals from $I to $200. The l e t t e r of offer explained that the hunter should return by mail either the enclosed check or his permit, postmarked no later than September 29 when the offer would expire.
This type of question is termed a "dichotomous choice"
question since each respondent must answer "yes or no to the specific offer. A total of 221 people (94 percent) returned~either t h e i r check or t h e i r permit.
A second sample of 353 hunters with permits was mailed a contingent
valuation survey.
With an incentive of $5 per questionnaire, 94 percent of
this group responded prior to the opening of the hunting season on October I . The primary contingent valuation question was worded to sound as much like the actual cash offers as possible, except that the hypothetical nature of the proposed transaction was emphasized. The amount offered again varied randomly from $I to $200. Each respondent was asked to state whether he or she would surrender the Horicon permit for the amount specified.
Later in the survey
each respondent was also asked a dichotomous choice willingness to pay question with the offers ranging from $I to $200 (see Bishop and Heberlein, 1979; and Bishop, et. al, 1983 for a more complete description of this experiment and subsequent analysis). The Sandhill Wildlife Demonstration Area, again located in Wisconsin, served as the site for Experiment I I (see Bishop, et. a l . , 1984, for a more detailed description of this experiment).
Sandhill, which is set aside for
w i l d l i f e research, contains twelve square miles of land surrounded by a deer-proof fence.
Special one-day hunts for deer of either sex have been held
there on the Saturday preceding the opening of the regular deer season. In order to hunt deer at Sandhill, regularly licensed hunters have needed a special permit.
These permits are issued free to winners of a lottery.
The 1983 Sandhill hunt for deer of either sex was held on November 12, 1983.
A t o t a l of 5,349 applications were received.
Prior to the hunt, the
staff of the Wisconsin Department of Natural Resources held a randomdrawing to determine the 150 applicants that would be allowed to hunt. The 1983 hunt not only authorized the issuance of 150 either-sex permits but also the issuance of four permits to the University of Wisconsin for research purposes. Becauseonly four permits were available, i t was necessary to use a sealed bid process. The 150 applicants randomly selected by the state to receive permits were divided into two groups of equal size.
The f i r s t group participated in a
sealed bid auction and the four lowest bidders were paid t h e i r bids in return for giving up t h e i r permits.
The second group participated in a hypothetical
103
sealed bid auction.
A total of 73 respondents in the real auction and 73
respondents in the hypothetical auction submitted bids.
To determine
willingness to pay, a random sample of 150 applicants who were u__nnsuccessful in the lottery participated in a sealed bid auction.
Half were informed that
they were part of an actual auction for a total of four Sandhill hunting permits and that their sealed bids would be entered into the auction at the amounts they stated.
Bid contracts for this group expressed a commitment to
pay the University of Wisconsin the amount of the bid if it was one of the four highest.
The other half of t h i s group submitted hypothetical sealed bids
on c o n t r a c t - l i k e forms.
Responses from a t o t a l of 68 p a r t i c i p a n t s in the
actual auction and 71 p a r t l c l p a n t s in the hypothetical auction were received. An auction followed by bidding was also tested.
A random sample of 150
a d d l t i o n a l unsuccessful applicants were assigned to real and hypothetical auctions.
The f i r s t
step of the bldding game was to s o l i c i t sealed bids in
exactly the fashion described in the preceding section except features.
The
contract specified that i t would be possible to change the bid l a t e r . Respondents were not informed that telephone bidding or any other mechanism f o r reconsidering t h e i r o f f e r would be i n s t i t u t e d .
A t o t a l of 66 I n d i v i d u a l s
in the actual auction and 70 l n d l v l d u a l s in the hypothetical auction returned the contract.
Telephone interviews were then conducted.
The telephone
interviewers were provided with scripts to f o l l o w when conducting the interviews and attempted to ascertain the subjects' maximum w i l l i n g n e s s - t o - p a y using an t t e r a t l v e bidding process.
A t o t a l of 65 I ndiv id u a ls in the real
auction and 62 I n d i v i d u a l s in the hypothetical auction were contacted in t h i s manner.
These f i n a l blds were entered Into the w i l l i n g n e s s - t o - p a y auction.
For f u r t h e r d e t a i l s on t h i s experiment, see Bishop et. al (1984) and Bishop and Heberlein ( i n press). Experiment I I I was conducted at Sandhtll a year l a t e r .
As in 1983, 150
permits were to be issued by l o t t e r y f o r the 1984 one day hunt f o r either-sex deer.
The University of Wisconsin was Issued up to 75 1984 Sandhill permits,
f o r the 1984 hunt.
This allowed the use of dichotomous cholce procedures
s i m i l a r to those used in experiment I rather than auctions. Half of the 150 hunters who received free 1984 Sandhtll permits In the state l o t t e r y received a l e t t e r explaining the study and a v a l i d check made out in the subject's name. The members of t h i s group were t o l d they had the choice of cashing the check and returning t h e i r permit or returning the check. to $539.
The amounts of the checks were selected at random and ranged from $16 This provided an actual behavior measure.
The other h a l f received
I d e n t i c a l dichotomous choice offers except that a l l offers were hypothetical. They were asked t f a check f o r $ ~ the permtt?
had been included, would they give up
Thls provided the contingent value, or the behavioral i n t e n t i o n .
104
To test willingness to pay measures, 150 hunters were selected at random from the population of applicants who did not receive a Sandhill permit in the lottery.
Half received a contract and explanatory material.
I f they executed
the contract, i t would allow them to buy one 1984 Sandhill permit for the amount stated in the contract.
The amounts specified in the contract ranged
from $18 to $512. The other half received the same offer except that a l l offers to this group were purely hypothetical.
Over 95 percent of the
willingness to sell group responded and 93 percent of the willingness to buy group responded. RESULTS Values were generated with l o g i t models in the dichotomous choice situations (see Bishop, et. al. 1983, IgB4 for a further discussion) and by computation of the arithmetic means in the auctions (Bishop, et. a l . , 1984). The comparison between CV (behavioral intention) values for selling permits and actual values for permits sold (or offered for sale) are displayed in Table I.
Using dichotomous choice, goose hunters' contingent values were
$101, or 60 percent higher than the actual value of $63. T h i s difference was s t a t i s t i c a l l y significant. situation was reversed.
Whenan auction was used for deer permits, the
The CV values were lower ($833 compared to $1,1B4),
although both values seemed very high for a one day hunt, and the difference was not s t a t i s t i c a l l y significant since the variances were quite large.
When
dichotomous choice was used to sell permits, the behavioral intention measure is much higher (almost 200~) than the actual behavior.
T h i s is a
s t a t i s t i c a l l y significant difference. TABLE l Behavioral intentions and actual behaviors for selling
Experiment
Commodity
Method
Dollar Values Behavioral Intentions
Behavior
I
Goose Permit
Dichotomous Choice
$101
$63
II
Deer Permits
Sealed Bid Auction
$833
$1,184
III
Deer Permits
Dichotomous Choice
$513
$1-/2
105
For willingness to pay, behavioral intentions are much closer to actual behaviors (Table 2).
In the sealed bid auction and the dichotomous choice
situation, the two are not s i g n i f i c a n t l y different, although the CV estimates are 33 percent higher in the former and 24 percent higher in the later cases. The r e l a t i v e l y small sample size does not allow us to establish the s t a t i s t i c a l significance of differences of this magnitude. The introduction of bidding further expands the difference to the point where the hypothetical values is 124 percent higher than the actual behavior measure.
TABLE 2 Behavioral intentions and actual behaviors for buying
Experiment
Commodity
Method
Dollar Values Behavioral Intentions
I
Goose Permit
Behavior
Dichotomous Choice
$21
a
Sealed Bid Auction
$32
$24
II
Deer Permits
Sealed Bid Auction & Bidding
$43
$1g
III
Deer Permits
Dichotomous Choice
$31
$25
aNo permits were available for us to sell so this value cannot be estimated. DISCUSSION I t appears that values based on behavioral intention measures of willingness to pay are only s l i g h t l y inflated from values obtained using actual market behaviors.
Willingness to sell behavioral intention measures
are much higher than comparable behavioral measures using dichotomous choices, and i f an auction format is used, the pattern is reversed.
Moreover, using
auctions gives willingness to sell values which are much higher than either BI or B for dichotomous choice on the same commodity. In short, willingness to sell contingent values are highly inflated and subject to a methods effect, while both behavioral intentions and actual market behavior are remarkably close for buying behavior independent of whether sealed bid auctions or dichotomous choice methods are chosen.
106
Beginning with the very f i r s t CV studies (Davis, 1963; Randall, et. a l . , 1974), researchers have sought to improve CV by introducing bidding to make the situation more r e a l i s t i c and to give individuals a chance to reflect on t h e i r judgments.
In the willingness to pay situation we added bidding and
found i t increased spread between behavioral intention and behavior, thus making CV less rather than more valld when using actual behavior as the criterion. The v a l i d i t y of Willingness to pay measures f i t s well with the social psychological theory.
Consumershave thousands of repeated experiences buying
things, so they develop r e l a t i v e l y clear ideas of what they would be w i l l i n g to pay.
In contrast, most people sell r e l a t i v e l y few things, especially
hunting permits in the United States and what they say they would sell them for has l i t t l e relationship to what they do when someonemakes them an offer. While i t might be theoretically or practically interesting to measure willingness to pay using CV, such efforts are very risky. Our finding in the 1984 experiment using real dollars, which showed that willingness to sell was much larger (about ? times) than willingness to pay, replicates the behavioral intention findings from the goose study and the 1983 deer study.
Manyother studies using behavioral intention only (see Cummings,
et. a l . , in press) have found these same kinds of striking differences.
Our
data here suggest that such differences are not a product of survey methodology and must be the subject of further study. While our willingness to pay results are optimistic, one should use considerable caution when generalizing to other areas such as willingness to pay for clean a i r or clean water.
Just because hunters can t e l l us reasonably
well what they w i l l pay for a hunting permit where the location, the time and the method of payment are well specified, does not necessarily mean that they know or can t e l l us on surveys what they w i l l pay for improved environmental quality.
Further research must explore v a l i d i t y for other environmental
goods. Our results, however, show some guarded optimism for the u t i l i t y of willingness to pay contingent valuations for some kinds of nonmarket goods.
REFERENCES
1 2
AJzen, I . " A t t i t u d i n a l vs normative messages: An i n v e s t i g a t i o n of the d i f f e r e n t i a l effects of persuasive communications on behavior," Sociometry, 1971, 34:263-280. Ajzen, I . and Flshbetn, R. "The p r e d i c t i o n of bebavlor from a t t i t u d i n a l and normative v a r i a b l e s , ' Journal of Experimental Social Psycholoqv, 1970, 6:466-487.
3
AJzen, I . and Flshbein, R. " A t t i t u d i n a l and normative varlables as predictors of s p e c i f i c behaviors," Journal of Personality and Soctal Psvcholoq¥, 1973, 27(1):41-57.
107
4
Bishop, R. C. and Heberletn, T. A. "Measuring values of extra market goods: Are t n d t r e c t methods blased?" American Journal of A g r i c u l t u r a l Economics, 1979, 61(5):926-930. 5 Btshop, R. C., Heberleln, T. A. and Kealy, M. J. "Contingent valuation of envlronmental assets: Comparisons with a simulated market," Natural Resources Journal, 1985, July, 23(3):619-34. 6 Bishop, R. C., Heberleln, T. A., Welsh, M. P. and Baumgartner, R. M. "Does contingent valuation work?: Results of the Sandhill experiment." Paper presented at the annual meeting of the Assoclation of Environmental and Resource Economists and the American A g r i c u l t u r a l Economics Association, 1984. 7 Btshop, R. C. and Heberleln T. A. "Does contingent valuatlon work?" in Cummings, R. G., Brookshire, S. and Schultz, W. O. (eds) Valutng Environmental Goods. Totawa, NJ: Rowan and Allanheld, in press. 8 Cummings, R. G., et. a l . Valulnq Environmental Goods. Totawa, NJ: Rowan and Allanheld, in press. 9 Davts, R. K. mRecreation plannlng as an economic problem," Natural Resources Journal, 1963, 3:239-249. 10 F1shbetn, M. ' A t t l t u d e s and the Prediction of Behavior," in Fishbetn, M. (ed) Readings In A t t i t u d e Theory and Measurement. New York: Wiley, 1967. 11McGulre, W. "The nature of a t t i t u d e s and a t t i t u d e change," in Llndzey, G. and Aronson, E. (eds), The Handbook of Social Psychology (2nd ed., Vol 3). Readlng, MA: Addison-Wesley, 1969. 12 Randall, A., et. a l . "Bidding games f o r valuation of aesthetic environmental improvements," Journal of Environmental Economics and Management, 1974, 1:132-149. 13 Rokeach, M. " A t t i t u d e s , " The I n t e r n a t i o n a l Encyclopedia of the Social Sciences, 1969, 1:449-459. 14 Schumen, H. and Johnson, M. "Attitudes and behavior," Annual Review of Socloloqv, 1976, 2:161-207.
99
ASSESSING THE VALIDITY OF CONTINGENTVALUATION: THREEFIELD EXPERIMENTS* T. A. HEBERLEINl and R. C. BISHOP2 l Department of Rural Sociology, University of Wisconsin, Madison, Wisconsin, USA 2 Department of Agricultural Economics, University of Wisconsin, Madison, Wisconsin, USA
ABSTRACT Contingent valuation, in social psychological terms, is a measure of behavioral intention (BI), or what people say they w i l l do on surveys. Market values, on the other hand, are obtained through observable buying and selling behaviors (B). The relationship between BI and B was explored in three f i e l d experiments. Hunters had an opportunity to sell t h e i r free but d i f f i c u l t to obtain hunting permits or buy such a permit. When i t came to selling permits in a take I t or leave i t situation, the amount people sald they would take was 60 percent higher in one experiment and 200 percent higher in the other than what they actually sold i t for. Willingness to sell values were greatly inflated by using a sealed bid auction, and In this case hunters said they would take less than they r e a l l y would take. For selling we conclude contingent valuation is not a good substitute for market behaviors. In contrast, willingness to pay is a much better indicator of what hunters actually pald to buy a permit. In two experiments, BI was 25 percent and 33 percent higher than B (N.S.). Further, the sealed bld auction gave the same results as dichotomous choice. Bidding in the willingness to pay situation increased the difference between BI and B. We speculated that because of repeated buying behaviors consumers have a pretty good idea of what they w i l l ~ay and can answer correctly on a survey. In contrast they seldom sell things, especially hunting permits, and do not have a good idea of what they r e a l l y w i l l sell for until confronted with cash. INTRODUCTION To obtain d o l l a r values for environmental goods which are not usually bought and sold in a market, economists have turned to survey research.
A
hypothetical market is set up where a respondent is asked in a survey the maximum amount he or she would pay for clean a i r or water or the minimum
*This research was supported by the College of A g r i c u l t u r e and L i f e Sciences, U n i v e r s i t y of Wisconsin, Madison, Resources f o r the Future I n c . , The Electrtc Power Research I n s t i t u t e , and the W i l d l i f e Management I n s t i t u t e . Thanks are due to our various research assistants Robert M. Baumgartner, Mary Jo Kealy, Michael P. Welsh and to the Wisconsin Department of Natural Resources p a r t i c u l a r l y Joseph C. Haug, Kent E. Kleptnger, John N. Kubtstak, and Ned Norton.
0048-9697/86/$03.50
© 1986 Elsevier Science Publishers B.V.
100
amount he or she would take in return for accepting some lower standard of environmental quality.
These responses to questionnaires are referred to as
contingent values since the d o l l a r values obtained are the amounts individuals say they are w i l l i n g to pay or receive contingent on the creation of a market. In cost-benefit analysis these contingent values are compared with market values of commodities which normally are bought and sold.
Contingent
valuation represents a real step forward in measuring environmental values and integrating these nonmarket values into decisions about the environment. The question remains, however, are the values people give in response to a survey really what they would pay or take in a real market with real dollars?
In
posing this question, economists have raised some fundamental social psychological issues.
In this paper we examine contingent valuation from this
view point and present experimental evidence on the v a l i d i t y of contingent valuation. CONTINGENT VALUATION: A SOCIAL PSYCHOLOGICAL PERSPECTIVE In social psychological terms, contingent values are behavioral intentions, not actions.
A behavioral intention is an unobservable psychological state
which must be inferred from questionnaire responses. A behavioral intention is one of the three t r a d i t i o n a l components of the attitude concept (McGuire, lg69; Rokeach, 1969; Fishbein, 1967). Liking or d i s l i k i n g (affect) and beliefs (cognition) are the other two components. Becausei t is a psychological variable, behavioral intentions may change with some rapidity. In contrast, a behavior is d i r e c t l y observable and once engaged in is a historical fact. The values obtained through a market process reflect results of many behaviors in the i n s t i t u t i o n a l context of a market, while contingent values a single intention to a hypothetical situation.
There exists in social
psychology a considerable debate about the relationship between behavioral intention and behavior.
Fishbein (1967, p. 48B) argues that in some cases
" . . . t h e correlation betweenmeasures of behavioral intention and the actual overt behavior is almost perfect."
Using prisoner dilemma games in laboratory
situations Ajzen and Fishbein found very high correlations between behavioral intentions and behaviors [ r = .B9 (Ajzen and Fishbein, 1970) r = .82 (Ajzen, IgTl)] and concluded that "...accurate behavioral prediction is possible when appropriate measures of behavioral intentions are obtained" (Ajzen and Fishbein, 1973, p. 49).
Fromthese studies one might conclude that contingent
values would be good surrogates for actual behavior and that CV measures from surveys could be d i r e c t l y and v a l i d l y compared with economic values obtained from behaviors in the market place.
I01 These high correlations between behavioral intentions (BI) and behavior (B) have, however, occurred in highly controlled situations where subjects had only two choices and were asked, after engaging in behaviors for a number of t r i a l s , how they intended to behave in the next series of t r i a l s . these cases we would expect the highest BI-B relationship.
I t is in
As Ajzen and
Fishbein (IgTO, p. 485) point out "a one to one relationship is expected i f , and only i f , BI is very specific to B and is measured immediately preceding the performance of B."
They also state (p. 4B6) that " . . . i t must be made
clear that an intention is only an intention, and in many cases, i t may not be possible for an individual to carry through his (sic) intentions because of various kinds of situational or interpersonal constraints.
While problems of
this kind can be avoided in the laboratory, i t may be necessary to consider them in f i e l d situations." Sociologists who are concerned with actual behavior in f i e l d settings have been more skeptical about the BI-B relationship.
Reviewing the sociological
l i t e r a t u r e beyond the laboratory Schuman and Johnson (1976) argue that a measured attitude is not a substitute for behavior.
The seminal and most
widely quoted study of the BI-B relation involved actual economic choices (La Piere, 1934). During the depression years of 1930-1932, hotels and restaurants a l l over the United States were surveyed by La Piere and said that they would not accept guests of a certain minority race (Chinese).
Whenthey
were confronted with Chinese guests who looked as i f they could pay, however, almost a l l did admit them as guests. Thus the observed behavior in this market transaction was dramatically different than the behavior intention. The point here is simply as Fishbein and Ajzen (1976, p. 580) argue " . . . t h e empirical relation between intention and behavior cannot be taken for granted but must be submitted to systematic empirical investigation." In this paper we are reporting the results of three f i e l d experiments where behavioral intentions (contingent values) as measures of behavior involving real money are obtained.
The f i r s t experiment involves the willingness to sell a goose
hunting permit, while the second two the willingness to sell or buy a deer hunting permit. THREE EXPERIMENTS Experiment I involved permits which authorized the bearer to take at most one Canada goose between October l and October 15, 1978 in an area around the 24,600 acre Horizon Marsh in central Wisconsin.
A hunter could legally
receive only one such permit, and a total of 13,g74 were issued by the Wisconsin Department of Natural Resources. The permits were free, but over 50,000 hunters apply for them.
102
A random sample was drawn of 237 hunters who had been issued a permit. Each received an actual cash offer to give up the permit.
Cash offers were
randomly determined ranging in roughly log-linear intervals from $I to $200. The l e t t e r of offer explained that the hunter should return by mail either the enclosed check or his permit, postmarked no later than September 29 when the offer would expire.
This type of question is termed a "dichotomous choice"
question since each respondent must answer "yes or no to the specific offer. A total of 221 people (94 percent) returned~either t h e i r check or t h e i r permit.
A second sample of 353 hunters with permits was mailed a contingent
valuation survey.
With an incentive of $5 per questionnaire, 94 percent of
this group responded prior to the opening of the hunting season on October I . The primary contingent valuation question was worded to sound as much like the actual cash offers as possible, except that the hypothetical nature of the proposed transaction was emphasized. The amount offered again varied randomly from $I to $200. Each respondent was asked to state whether he or she would surrender the Horicon permit for the amount specified.
Later in the survey
each respondent was also asked a dichotomous choice willingness to pay question with the offers ranging from $I to $200 (see Bishop and Heberlein, 1979; and Bishop, et. al, 1983 for a more complete description of this experiment and subsequent analysis). The Sandhill Wildlife Demonstration Area, again located in Wisconsin, served as the site for Experiment I I (see Bishop, et. a l . , 1984, for a more detailed description of this experiment).
Sandhill, which is set aside for
w i l d l i f e research, contains twelve square miles of land surrounded by a deer-proof fence.
Special one-day hunts for deer of either sex have been held
there on the Saturday preceding the opening of the regular deer season. In order to hunt deer at Sandhill, regularly licensed hunters have needed a special permit.
These permits are issued free to winners of a lottery.
The 1983 Sandhill hunt for deer of either sex was held on November 12, 1983.
A t o t a l of 5,349 applications were received.
Prior to the hunt, the
staff of the Wisconsin Department of Natural Resources held a randomdrawing to determine the 150 applicants that would be allowed to hunt. The 1983 hunt not only authorized the issuance of 150 either-sex permits but also the issuance of four permits to the University of Wisconsin for research purposes. Becauseonly four permits were available, i t was necessary to use a sealed bid process. The 150 applicants randomly selected by the state to receive permits were divided into two groups of equal size.
The f i r s t group participated in a
sealed bid auction and the four lowest bidders were paid t h e i r bids in return for giving up t h e i r permits.
The second group participated in a hypothetical
103
sealed bid auction.
A total of 73 respondents in the real auction and 73
respondents in the hypothetical auction submitted bids.
To determine
willingness to pay, a random sample of 150 applicants who were u__nnsuccessful in the lottery participated in a sealed bid auction.
Half were informed that
they were part of an actual auction for a total of four Sandhill hunting permits and that their sealed bids would be entered into the auction at the amounts they stated.
Bid contracts for this group expressed a commitment to
pay the University of Wisconsin the amount of the bid if it was one of the four highest.
The other half of t h i s group submitted hypothetical sealed bids
on c o n t r a c t - l i k e forms.
Responses from a t o t a l of 68 p a r t i c i p a n t s in the
actual auction and 71 p a r t l c l p a n t s in the hypothetical auction were received. An auction followed by bidding was also tested.
A random sample of 150
a d d l t i o n a l unsuccessful applicants were assigned to real and hypothetical auctions.
The f i r s t
step of the bldding game was to s o l i c i t sealed bids in
exactly the fashion described in the preceding section except features.
The
contract specified that i t would be possible to change the bid l a t e r . Respondents were not informed that telephone bidding or any other mechanism f o r reconsidering t h e i r o f f e r would be i n s t i t u t e d .
A t o t a l of 66 I n d i v i d u a l s
in the actual auction and 70 l n d l v l d u a l s in the hypothetical auction returned the contract.
Telephone interviews were then conducted.
The telephone
interviewers were provided with scripts to f o l l o w when conducting the interviews and attempted to ascertain the subjects' maximum w i l l i n g n e s s - t o - p a y using an t t e r a t l v e bidding process.
A t o t a l of 65 I ndiv id u a ls in the real
auction and 62 I n d i v i d u a l s in the hypothetical auction were contacted in t h i s manner.
These f i n a l blds were entered Into the w i l l i n g n e s s - t o - p a y auction.
For f u r t h e r d e t a i l s on t h i s experiment, see Bishop et. al (1984) and Bishop and Heberlein ( i n press). Experiment I I I was conducted at Sandhtll a year l a t e r .
As in 1983, 150
permits were to be issued by l o t t e r y f o r the 1984 one day hunt f o r either-sex deer.
The University of Wisconsin was Issued up to 75 1984 Sandhill permits,
f o r the 1984 hunt.
This allowed the use of dichotomous cholce procedures
s i m i l a r to those used in experiment I rather than auctions. Half of the 150 hunters who received free 1984 Sandhtll permits In the state l o t t e r y received a l e t t e r explaining the study and a v a l i d check made out in the subject's name. The members of t h i s group were t o l d they had the choice of cashing the check and returning t h e i r permit or returning the check. to $539.
The amounts of the checks were selected at random and ranged from $16 This provided an actual behavior measure.
The other h a l f received
I d e n t i c a l dichotomous choice offers except that a l l offers were hypothetical. They were asked t f a check f o r $ ~ the permtt?
had been included, would they give up
Thls provided the contingent value, or the behavioral i n t e n t i o n .
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To test willingness to pay measures, 150 hunters were selected at random from the population of applicants who did not receive a Sandhill permit in the lottery.
Half received a contract and explanatory material.
I f they executed
the contract, i t would allow them to buy one 1984 Sandhill permit for the amount stated in the contract.
The amounts specified in the contract ranged
from $18 to $512. The other half received the same offer except that a l l offers to this group were purely hypothetical.
Over 95 percent of the
willingness to sell group responded and 93 percent of the willingness to buy group responded. RESULTS Values were generated with l o g i t models in the dichotomous choice situations (see Bishop, et. al. 1983, IgB4 for a further discussion) and by computation of the arithmetic means in the auctions (Bishop, et. a l . , 1984). The comparison between CV (behavioral intention) values for selling permits and actual values for permits sold (or offered for sale) are displayed in Table I.
Using dichotomous choice, goose hunters' contingent values were
$101, or 60 percent higher than the actual value of $63. T h i s difference was s t a t i s t i c a l l y significant. situation was reversed.
Whenan auction was used for deer permits, the
The CV values were lower ($833 compared to $1,1B4),
although both values seemed very high for a one day hunt, and the difference was not s t a t i s t i c a l l y significant since the variances were quite large.
When
dichotomous choice was used to sell permits, the behavioral intention measure is much higher (almost 200~) than the actual behavior.
T h i s is a
s t a t i s t i c a l l y significant difference. TABLE l Behavioral intentions and actual behaviors for selling
Experiment
Commodity
Method
Dollar Values Behavioral Intentions
Behavior
I
Goose Permit
Dichotomous Choice
$101
$63
II
Deer Permits
Sealed Bid Auction
$833
$1,184
III
Deer Permits
Dichotomous Choice
$513
$1-/2
105
For willingness to pay, behavioral intentions are much closer to actual behaviors (Table 2).
In the sealed bid auction and the dichotomous choice
situation, the two are not s i g n i f i c a n t l y different, although the CV estimates are 33 percent higher in the former and 24 percent higher in the later cases. The r e l a t i v e l y small sample size does not allow us to establish the s t a t i s t i c a l significance of differences of this magnitude. The introduction of bidding further expands the difference to the point where the hypothetical values is 124 percent higher than the actual behavior measure.
TABLE 2 Behavioral intentions and actual behaviors for buying
Experiment
Commodity
Method
Dollar Values Behavioral Intentions
I
Goose Permit
Behavior
Dichotomous Choice
$21
a
Sealed Bid Auction
$32
$24
II
Deer Permits
Sealed Bid Auction & Bidding
$43
$1g
III
Deer Permits
Dichotomous Choice
$31
$25
aNo permits were available for us to sell so this value cannot be estimated. DISCUSSION I t appears that values based on behavioral intention measures of willingness to pay are only s l i g h t l y inflated from values obtained using actual market behaviors.
Willingness to sell behavioral intention measures
are much higher than comparable behavioral measures using dichotomous choices, and i f an auction format is used, the pattern is reversed.
Moreover, using
auctions gives willingness to sell values which are much higher than either BI or B for dichotomous choice on the same commodity. In short, willingness to sell contingent values are highly inflated and subject to a methods effect, while both behavioral intentions and actual market behavior are remarkably close for buying behavior independent of whether sealed bid auctions or dichotomous choice methods are chosen.
106
Beginning with the very f i r s t CV studies (Davis, 1963; Randall, et. a l . , 1974), researchers have sought to improve CV by introducing bidding to make the situation more r e a l i s t i c and to give individuals a chance to reflect on t h e i r judgments.
In the willingness to pay situation we added bidding and
found i t increased spread between behavioral intention and behavior, thus making CV less rather than more valld when using actual behavior as the criterion. The v a l i d i t y of Willingness to pay measures f i t s well with the social psychological theory.
Consumershave thousands of repeated experiences buying
things, so they develop r e l a t i v e l y clear ideas of what they would be w i l l i n g to pay.
In contrast, most people sell r e l a t i v e l y few things, especially
hunting permits in the United States and what they say they would sell them for has l i t t l e relationship to what they do when someonemakes them an offer. While i t might be theoretically or practically interesting to measure willingness to pay using CV, such efforts are very risky. Our finding in the 1984 experiment using real dollars, which showed that willingness to sell was much larger (about ? times) than willingness to pay, replicates the behavioral intention findings from the goose study and the 1983 deer study.
Manyother studies using behavioral intention only (see Cummings,
et. a l . , in press) have found these same kinds of striking differences.
Our
data here suggest that such differences are not a product of survey methodology and must be the subject of further study. While our willingness to pay results are optimistic, one should use considerable caution when generalizing to other areas such as willingness to pay for clean a i r or clean water.
Just because hunters can t e l l us reasonably
well what they w i l l pay for a hunting permit where the location, the time and the method of payment are well specified, does not necessarily mean that they know or can t e l l us on surveys what they w i l l pay for improved environmental quality.
Further research must explore v a l i d i t y for other environmental
goods. Our results, however, show some guarded optimism for the u t i l i t y of willingness to pay contingent valuations for some kinds of nonmarket goods.
REFERENCES
1 2
AJzen, I . " A t t i t u d i n a l vs normative messages: An i n v e s t i g a t i o n of the d i f f e r e n t i a l effects of persuasive communications on behavior," Sociometry, 1971, 34:263-280. Ajzen, I . and Flshbetn, R. "The p r e d i c t i o n of bebavlor from a t t i t u d i n a l and normative v a r i a b l e s , ' Journal of Experimental Social Psycholoqv, 1970, 6:466-487.
3
AJzen, I . and Flshbein, R. " A t t i t u d i n a l and normative varlables as predictors of s p e c i f i c behaviors," Journal of Personality and Soctal Psvcholoq¥, 1973, 27(1):41-57.
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4
Bishop, R. C. and Heberletn, T. A. "Measuring values of extra market goods: Are t n d t r e c t methods blased?" American Journal of A g r i c u l t u r a l Economics, 1979, 61(5):926-930. 5 Btshop, R. C., Heberleln, T. A. and Kealy, M. J. "Contingent valuation of envlronmental assets: Comparisons with a simulated market," Natural Resources Journal, 1985, July, 23(3):619-34. 6 Bishop, R. C., Heberleln, T. A., Welsh, M. P. and Baumgartner, R. M. "Does contingent valuation work?: Results of the Sandhill experiment." Paper presented at the annual meeting of the Assoclation of Environmental and Resource Economists and the American A g r i c u l t u r a l Economics Association, 1984. 7 Btshop, R. C. and Heberleln T. A. "Does contingent valuatlon work?" in Cummings, R. G., Brookshire, S. and Schultz, W. O. (eds) Valutng Environmental Goods. Totawa, NJ: Rowan and Allanheld, in press. 8 Cummings, R. G., et. a l . Valulnq Environmental Goods. Totawa, NJ: Rowan and Allanheld, in press. 9 Davts, R. K. mRecreation plannlng as an economic problem," Natural Resources Journal, 1963, 3:239-249. 10 F1shbetn, M. ' A t t l t u d e s and the Prediction of Behavior," in Fishbetn, M. (ed) Readings In A t t i t u d e Theory and Measurement. New York: Wiley, 1967. 11McGulre, W. "The nature of a t t i t u d e s and a t t i t u d e change," in Llndzey, G. and Aronson, E. (eds), The Handbook of Social Psychology (2nd ed., Vol 3). Readlng, MA: Addison-Wesley, 1969. 12 Randall, A., et. a l . "Bidding games f o r valuation of aesthetic environmental improvements," Journal of Environmental Economics and Management, 1974, 1:132-149. 13 Rokeach, M. " A t t i t u d e s , " The I n t e r n a t i o n a l Encyclopedia of the Social Sciences, 1969, 1:449-459. 14 Schumen, H. and Johnson, M. "Attitudes and behavior," Annual Review of Socloloqv, 1976, 2:161-207.