Calibrating hypothetical willingness to pay responses

Experimental data comparing hypothetical and real dichotomous choice respon ses for two different goods were used to estimate a statistical bias functi on to calibrate the hypothetical yes responses. The probability that a hypo thetical yes response would be a real yes response was estimated as a funct ion of the individual's self-assessed certainty of the hypothetical yes res ponse (assessed on a 0-10 scale) and a variable representing the price leve l. Without calibration the hypothetical yes responses significantly exceede d the proportion of real yes responses, but after calibration the null hypo thesis of no difference between hypothetical and real responses could not b e rejected in any of the experiments.