This study focuses on how the disparity between willingness to pay (WTP) and willingness to accept (WTA) values affect VSL and the important of choice of measure. We used the survey-based choice experiment method, which was conducted in Laos and Thailand, to clarify the disparity between WTP and WTA measures in the context of the changes in the risk of dying from cancer. The results from our survey clearly indicated that the disparity between WTP and WTA for identical changes in the risk of dying from cancer exists. Specifically, the WTA values were significantly larger than those of the WTP measure. This result first suggests that using WTP as a universal measure for calculating VSL may not be appropriate. In addition to that, this study also found the sign that people may treat reduction in risk of dying from cancer as a reduction of loss instead of gain as previously assumed in many studies. Although this study cannot clarify this issue, this implication is highly significant; if people treat reduction of risk as a reduction of loss, then the appropriate measure for this change would be WTA rather than WTP. Using the wrong measure would result in biased estimate and according to policy design.

How Should the Value of Statistical Life be Measured? The Effect of the Disparity between the Measures of Willingness to Pay and Willingness to Accept
How Should the Value of Statistical Life be Measured? The Effect of the Disparity between the Measures of Willingness to Pay and Willingness to Accept