To claim or not to claim: Anonymity, symmetric externalities and honesty

In many situations, economic actors submit claims for money which are unverifiable or hard to verify. Examples include claims for a tax return or an insurance payout. This paper investigates what role anonymity and externalities play for the decision of whether to be (dis)honest when making such claims. First, does honest claiming increase when anonymity is removed and unverified claims are made public? We present experimental evidence to this effect. Second, does honest reporting increase when it is public knowledge that claims affect others’ payoffs and claimants’ payoffs are symmetrically affected by others’ claims? We find no such effect. Making claims public and having symmetric externalities together increases honesty, but this effect is driven solely by the reduction in anonymity.