Are Internet Surveys an Alternative to Face-to Face Interviews in Contingent Valuation?

Internet is an increasingly popular data collection mode for stated preference research in environmental economics. However, little is known about how this survey mode may influence data quality and welfare estimates. As part of a national contingent valuation (CV) survey estimating willingness to pay (WTP) for biodiversity protection plans, we assign two groups of respondents either to an Internet or face-to-face (in-home) interview mode. Our design aims to better isolate measurement effects from sample composition effects by drawing both samples from the same sample frame. We find little evidence of social desirability bias in the interview setting or satisficing (shortcutting the response process) in the Internet survey. The share of ldquo;don't knowsrdquo;, zeros and protest responses to the WTP question with a payment card is very similar between modes and equality of mean WTP cannot be rejected. Results are fairlyencouraging for the use of Internet in CV as stated preferences do not seem to besignificantly different or biased compared to face-to-face interviews