External Validity of Contingent Valuation: Comparing Hypothetical and Actual Payments
通过首次现场样本内测试，比较假设支付与实际支付，发现假设回答中“是”的比例高于实际，而确定性校准可缩小差距，提高政策建议准确性。
Whilst contingent valuation is increasingly used in economics to value benefits, questions remain concerning its external validity that is do hypothetical responses match actual responses? We present results from the first within sample field test. Whilst Hypothetical No is always an Actual No, Hypothetical Yes exceed Actual Yes responses. A constant rate of response reversals across bids/prices could suggest theoretically consistent option value responses. Certainty calibrations (verbal and numerical response scales) minimise hypothetical-actual discrepancies offering a useful solution. Helping respondents resolve uncertainty may reduce the discrepancy between hypothetical and actual payments and thus lead to more accurate policy recommendations. Copyright © 2016 John Wiley & Sons, Ltd.