Searching for a better willingness to pay elicitation method in rural Nigeria: the binary question with follow-up method versus the bidding game technique.

OBJECTIVES: To compare the theoretical validity and predictive validity of the binary with follow-up questions technique and the bidding game, using hypothetical and actual WTP for insecticide-treated nets (ITNs) in Nigeria.
METHODS: Each elicitation method was applied in one of two rural communities in Enugu state, Nigeria. A pre-tested interviewer-administered questionnaire was administered to household heads or representatives of households. WTP was elicited in each after presenting the scenario and showing a sample of the ITNs to the respondents. Then, within an interval of 1-2 months, the nets were sold to the respondents to compare hypothetical and actual WTP.
FINDINGS: Consistent slightly higher mean and median WTP amounts were elicited from Mbano where the bidding game was used. The WTP technique was able to predict WTP responses correctly in 75% and 85% of cases in Orba and Mbano, respectively. Chi-square analysis did not show any statistical difference in values from both communities (p>0.05).
CONCLUSION: Though the two techniques yielded similar results, the thrust should be the development of a WTP elicitation method that best mimics the bargaining process in normal market situations in rural Nigeria. Such an indigenous technique will help improve the predictive validity of the contingent valuation method. Copyright 2001 John Wiley & Sons, Ltd.