Ex post mitigation of hypothetical bias using follow up certainty questions typically takes one of two forms: (1) two options, "definitely sure" and "probably sure", or (2) a 10-point scale with 10 very certain. While both have been successful in eliminating hypothetical bias from estimates of...

Concern exists that hypothetical willingness to pay questions overestimate real willingness to pay. In a field experiment, we compare two methods of removing hypothetical bias, a cheap talk approach and a certainty approach, with real purchases. We find evidence of hypothetical bias for...