多財貨雙界二元選擇條件評估起始點偏誤校正模型之建構－改善三高危險因子對心血管疾病願付價值的評估

Abstract

Even previous studies had provided tests and constructed models for correcting the starting point bias induced by offered bids for data collected both from single-bounded and double-bounded dichotomous choice contingent valuation method. However, willingness to pay for a set of substitute and/or complement multiple goods evaluated by a double-bounded dichotomous choice will not only be affected by the offered bids of the goods being evaluated itself but also the offered bids provided for the goods being evaluated sequentially. As a result, if such effect is not taking into account the mean willingness to pay from a double-bounded dichotomous choice evaluation will be biased. The purpose of this study is to construct a model for correcting the starting point bias with the offered bids provided for certain good being evaluated and account for offered bids provided for the potential substitution and complementarity goods proposed beforehand. The empirical examination is then performed for three major risk factors of cardiovascular disease, in which these three factors are evaluated in a sequence and the information is released to respondents one at a time. The mean willingness to pay are computed and compared between the modified and unmodified models. The empirical evidence show that there exists a relationship between risk factors, i.e. these three factors can not be treated separated as if they were irrelevant. A strong anchoring effect results in overestimating the benefits of three major modifiable cardiovascular risk factors in unmodified model. Therefore, the model constructed in this study is an ideal model to estimate the mean willingness to pay for these three major factors in computing the total benefit of preventing the cardiovascular disease.