Civic honesty around the globe

The disadvantage of using a clear business-card case over a traditional wallet is clear, in that it is relatively unusual. The advantage of using a clear case, however, is that it affords considerably more experimental control in that you can be relatively certain that every recipient knows what is inside. With a wallet, there will be variation in who decides to inspect the wallet, and that introduces selection effects into the experimental design (i.e., are those who are willing to look inside a wallet, compared to those who don't, different in their degree of honesty?). This makes interpreting the evidence a lot more challenging.

FWIW we examined how our measure of civic honesty compares to other known proxies of honest behavior (tax evasion, corruption, etc) within and between countries. If there was something artificial or unique about our setting -- such as using unusual clear business card cases -- then you wouldn't expect our results to generalize or correlate with other measures of honest behavior. However, we find response rates correlate very highly with these other proxies of honesty, suggesting that they are tapping into some broader construct.