Internet is quickly becoming the survey mode of choice for stated preference (SP) surveys in environmental economics. However, this choice is being made with relatively little consideration of its potential influence on survey results. This paper reviews the theory and emerging evidence of mode...

The aggregate welfare measure for a change in the provision of a public good derived from a contingent valuation (CV) survey will be much higher if the same elicited mean willingness to pay (WTP) is added up over individuals rather than households. A trivial fact, however, once respondents are...