Stated preference scenarios often provide information on intermediate biophysical processes but omit information on the resulting final services that provide utility. This may cause respondents to speculate about the effects of intermediate outcomes on their welfare, leading to biased welfare...

A survey with validation question was delivered to 3475 respondents to study the impact of using validation question to improve data quality. Results show that The respondents who passed the validation question had significantly older ages, higher median incomes and higher education levels. The...