Meta-analysis of consumer's willingness-to-pay premiums for certified wood products

Consumers’ willingness to pay (WTP) price premiums for environmentally certified wood products has been frequently estimated using stated preference methods. Estimates of WTP premiums for certified wood products over non-certified options reported in the literature range from 1.0% to 39.3%. This paper describes a meta-analysis used to determine the key factors associated with WTP price premium estimates by examining data from 19 different studies conducted around the world. Results of Bayesian hierarchical models show that frequently purchased wood products and wood products with lower base prices tend to capture higher percentage premiums. Survey administration method was also a statistically significant factor influencing variations in WTP estimates. Results show that conjoint analysis elicited inflated WTP estimates toward certified wood products compared with contingent valuation methods. Reported WTP estimates have increased in recent years. Recommendations to reduce the error of WTP estimates toward certified wood products and improve the validity of experimental studies are provided.