Selective assessment and positivity bias in environmental valuation.

The need to determine the value of environmental entities has generated substantial research regarding optimal methods for obtaining valuations from survey respondents. The literature suggests the importance of providing clear, complete descriptions of the entity being valued prior to respondents indicating their valuations. The target entity's attributes are often presented in isolation or in greater detail compared with other entities. Two experiments were conducted to explore whether selective exposure to and assessment of an environmental entity can bias survey respondents' judgments. This article adds to the environmental valuation literature by demonstrating a new process that leads to value overestimates. Specifically, the article shows that (a) when an environmental entity is the focus of assessment in a survey, positively biased evaluations often result; (b) positivity bias in evaluation translates to real monetary allocation decisions; and (c) selective information processing contributes to these effects.