A Comparison of Hypothetical Phone and Mail Contingent Valuation Responses for Green-Pricing Electricity Programs

This study provides the first contingent valuation phone-mail comparison that meets current standards for response rates, draws from a general population, is relevant to the valuation of general environmental goods, and allows comparisons with actual participation rates. Social desirability effects are found to be more prevalent in phone responses to subjective questions, but do not appear to affect hypothetical participation decisions: calibrated and uncalibrated hypothetical participation rates are statistically similar across modes. As such, neither mode appears to dominate from the perspective of providing more valid estimates of actual participation decisions.