Costly Sanctions and the Treatment of Frequent Violators in Regulatory Settings

Regulators typically treat frequent violators more harshly. When does such harsh treatment maximize overall compliance? We consider the role of two factors: responsiveness to penalties and costs of sanctions. A novel insight is that maintaining a credible threat of sanction against infrequent violators is relatively cheap because that threat seldom needs to be backed up. In a Clean Water Act application, the marginal sanction deters ten times as many violations when directed at infrequent violators. On net, this is due to a sanction cost effect, not because infrequent violators are marginally more responsive to the threat of punishment.