Thomas C. Brown

Explaining the Discrepancy between Intentions and Actions: The Case of Hypothetical Bias in Contingent Valuation:

An experiment was designed to account for intention-behavior discrepancies by applying the theory of planned behavior to contingent valuation. College students (N = 160) voted in hypothetical and real payment referenda to contribute

The complementary relationship in estimation of regional evapotranspiration: An enhanced advection-aridity model

8 to a scholarship fund. Overestimates of willingness to pay in the hypothetical referendum could not be attributed to moderately favorable latent dispositions. Instead, this hypothetical bias was explained by activation of more favorable beliefs and attitudes in the context of a hypothetical rather than a real referendum. A corrective entreaty was found to eliminate this bias by bringing beliefs, attitudes, and intentions in line with those in the real payment situation. As a result, the theory of planned behavior produced more accurate prediction of real payment when participants were exposed to the corrective entreaty.

The complementary relationship in estimation of regional evapotranspiration: the Complementary Relationship Areal Evapotranspiration and Advection-Aridity models

Long-term monthly evapotranspiration estimates from Brutsaert and Strickers Advection-Aridity model were compared with independent estimates of evapotranspiration derived from long-term water balances for 139 undisturbed basins across the conterminous United States. On an average annual basis for the period 1962-1988 the original model, which uses a Penman wind function, underestimated evapotranspiration by 7.9% of precipitation compared with the water balance estimates. Model accuracy increased with basin humidity. An improved formulation of the model is presented in which the wind function and the Priestley-Taylor coefficient are modified. The wind function was reparameterized on a seasonal, regional basis to replicate independent proxy potential evapotranspiration surfaces. This led to significant differences from the original Penman wind function. The reparameterized wind function, together with a recalibrated Priestley- Taylor coefficient in the wet environment evapotranspiration formulation, reduced the underestimation of annual average evapotranspiration to only 1.15% of precipitation on an independent set of validation basins. The results offered here lend further support for Bouchets hypothesis as it applies to large-scale, long-term evapotranspiration.

Why the WTA-WTP disparity matters

Two implementations of the complementary relationship hypothesis for regional evapotranspiration, the Complementary Relationship Areal Evapotranspiration (CRAE) model and the Advection-Aridity (AA) model, are evaluated against independent estimates of regional evapotranspiration derived from long-term, large-scale water balances (1962-1988) for 120 minimally impacted basins in the conterminous United States. The CRAE model overestimates annual evapotranspiration by 2.5% of mean annual precipitation, and the AA model underestimates annual evapotranspiration by 10.6% of precipitation. Generally, increasing humidity leads to decreasing absolute errors for both models, and increasing aridity leads to increasing overestimation by the CRAE model and underestimation by the AA model, with the exception of high, arid basins, where the AA model overestimates evapotranspiration. Overall, the results indicate that the advective portion of the AA model must be recalibrated before it may be used successfully on a regional basis and that the CRAE model accurately predicts monthly regional evapotranspiration.

Further tests of entreaties to avoid hypothetical bias in referendum contingent valuation

Abstract The disparity between willingness to pay (WTP) and willingness to accept compensation (WTA) has been demonstrated repeatedly. Because using WTP estimates of value where a WTA estimate is appropriate tends to undervalue environmental assets, this issue is important to environmental managers. We summarize reasons for the disparity and then discuss some of the implications for management of environmental assets. We end by suggesting some approaches for dealing with the lack of credible methods for estimating WTA values of environmental goods.

Contingent Valuation and Incentives

Abstract Over-estimation of willingness to pay in contingent markets has been attributed largely to hypothetical bias. One promising approach for avoiding hypothetical bias is to tell respondents enough about such bias that they self-correct for it. A script designed for this purpose by Cummings and Taylor was used in hypothetical referenda that differed in payment amount. In comparisons with behavior observed in otherwise identical real payment referenda, the script worked remarkably well at higher payment levels (dropping the likelihood of a yes vote to the level obtained in separate sample real referenda), but less well at a lower payment level. The repeated success of the script at higher payment amounts is a clear sign that additional research is warranted—research that will bring us a more complete understanding of how the entreaty works. This research may need to explore its workings at the individual respondent level.

Observational evidence of the complementary relationship in regional evaporation lends strong support for Bouchet's hypothesis

We empirically investigate the effect of the payment mechanism on contingent values by asking a willingness-to-pay question with one of three different payment mechanisms: individual contribution, contribution with provision point, and referendum. We find statistical evidence of more affirmative responses in the referendum treatment relative to the individual contribution treatment, some weak statistical evidence of more affirmative responses in the referendum treatment relative to the provision point treatment, and no statistical evidence of more affirmative responses in the provision point treatment relative to the individual contribution treatment. The relative credibility of the three payment mechanisms is also examined. (JEL H41, Q26)

Evaluating the Validity of the Dichotomous Choice Question Format in Contingent Valuation

Using independent observations of actual and potential evapotranspiration at a wide range of spatial scales, we provide direct observational evidence of the complementary relationship in regional evapotranspiration hypothesized by Bouchet in 1963. Bouchet proposed that, for large homogeneous surfaces with minimal advection of heat and moisture, potential and actual evapotranspiration depend on each other in a complementary manner through land-atmosphere feedbacks. Although much work has been done that has led to important theoretical and conceptual insights about regional actual evapotranspiration and its relation to regional potential evapotranspiration, never before has a data set of direct observations been assembled that so clearly displays complementarity, providing strong evidence for the complementary relationship hypothesis, and raising its status above that of a mere conjecture.

Is motion more important than it sounds?: The medium of presentation in environment perception research

Hypothetical and actual cash willingness to pay (WTP) for an art print were elicited with dichotomous choice and open-ended question formats. Comparing hypothetical and actual dichotomous choice responses using both a likelihood ratio test and the method of convolutions suggests we reject equality at the 0.05 but not the 0.01 level. Hypothetical WTP was roughly two times actual WTP with the dichotomous choice format. There were no significant differences between the open-ended and dichotomous choice question formats when both were used to estimate hypothetical WTP or both used to estimate actual WTP.

Be careful what you wish for: the legacy of Smokey Bear

This study assessed the incremental validity of different media for representing landscapes with significant dynamic elements. The experimental design independently varied the presence of motion and sound in different representations of a wild and scenic river in order to evaluate the adequacy or sufficiency of the surrogate to reflect physical changes in the landscape. Three representational conditions were identified: (1) video/sound, (2) video/no sound, and (3) static/no sound. A pilot study assessed the ability of the static images to represent river flow levels per se, and confirmed comparability with prior results (Brown & Daniel, 1989, Journal of Environmental Psychology, 7, 233–250). Scenic beauty judgments were then collected within each representational condition. Multiple regression analyses were used to determine the relationship of flow level to perceived scenic beauty for each representation condition. The results demonstrated that motion and sound, individually and conjointly, influenced judgements of scenic beauty for a landscape with a significant dynamic element.