Strazzera, Elisabetta; Scarpa, Riccardo; Calia, Pinuccia; … - In: Applied Economics 35 (2003) 2, pp. 133-138
In contingent valuation surveys the category of zero bidders refers to individuals that are not willing to pay anything for the programme under analysis. Specific questions can help to identify true zero values, coming from people that are indifferent to the programme, separately from protest...