Certainty of Punishment versus Severity of Punishment
首次系统比较了惩罚确定性与严厉性在环境保护中的威慑效果，发现两者在高水平下均有效，但确定性更有效；低水平下增加两者反而适得其反。
According to the standard enforcement model, the key deterrence components are punishment certainty and severity. While theory predicts the relative efficacy of certainty versus severity, empirical and experimental evidence are mixed. Our study represents the first to systematically compare the effects of certainty and severity in the environmental protection context. Our empirics examine wastewater discharged by chemical manufacturing facilities permitted under the Clean Water Act. We find that, when enforcement certainty and severity are high, both components effectively deter pollution, with certainty more effective. In contrast, certainty and severity increases prove counter-productive when certainty and severity are low.