Penn, Jerrod M.

May, 2019

By: Penn, Jerrod M.; Hu, Wuyang; Cox, Linda J.
In a choice experiment, when respondents are not given the opportunity to choose none of the options offered in a choice set, the choices can be considered forced. In this study of visits to Hawaiian beaches, we adopt a dual-response choice experiment that allows a comparison between forced and unforced choices while avoiding the possible confounding effect of choice set complexity found in previous research. The results suggest that individual willingness to pay is different in forced and unforced choice sets. Joint tests for parameter equality provide evidence to support the use of unforced choice designs.

January, 2018

By: Zhong, Hua; Hu, Wuyang; Penn, Jerrod M.
Missing-data problems are common in farmer surveys but are often ignored in the literature. Conventional methods to address missing data, such as deletion and mean replacement, assume that data are missing completely at random, which rarely holds. This study compares these approaches to the multiple imputation method, which produces different parameter estimates. The mean replacement method increases the central tendency of data, leading to more significant but smaller coefficients than the other methods. We recommend using both the deletion and multiple imputation methods to deal with missing data; results generated by the mean replacement method may not be as reliable.