Can unbiased be tighter? Assessment of methods to reduce the bias-variance trade-off in WTP estimation

This paper aims at verifying the claim, appeared in recent literature, that it is possible to control for response bias associated to the double bound elicitation method, while keeping gains in efficiency of the WTP estimates. Results from a Monte Carlo analysis lead, in general, to reject the claim; but when initial bids are not correctly chosen, the gains in efficiency are confirmed. An empirical application dealing with WTP estimation for drinking water quality improvements illustrates a case where a flexible modeling approach based on Copula distributions allows relevant gains with respect to the Single Bound estimator.