Shackley Phil, Dixon Simon
School of Health and Related Research, University of Sheffield, Sheffield, UK.
Health Econ. 2014 Oct;23(10):1213-23. doi: 10.1002/hec.2980. Epub 2013 Aug 6.
Willingness to pay (WTP) values derived from contingent valuation surveys are prone to a number of biases. Range bias occurs when the range of money values presented to respondents in a payment card affects their stated WTP values. This paper reports the results of an exploratory study whose aim was to investigate whether the effects of range bias can be reduced through the use of an alternative to the standard payment card method, namely, a random card sort method. The results suggest that the random card sort method is prone to range bias but that this bias may be mitigated by restricting the analysis to the WTP values of those respondents who indicate they are 'definitely sure' they would pay their stated WTP.
通过条件估值调查得出的支付意愿（WTP）值容易出现多种偏差。当支付卡中呈现给受访者的货币价值范围影响他们声明的WTP值时，就会出现范围偏差。本文报告了一项探索性研究的结果，其目的是调查是否可以通过使用标准支付卡方法的替代方法，即随机卡片排序方法，来减少范围偏差的影响。结果表明，随机卡片排序方法容易出现范围偏差，但通过将分析限制在那些表示“绝对确定”会支付其声明的WTP的受访者的WTP值上，这种偏差可能会得到缓解。
