Sue H. Mialon (Emory University) has posted Declining Moral Standards and the Role of Law on SSRN. Here is the abstract:
This paper models how moral rules form through social learning. Members of society learn morality by observing the behavior of other members. Their incentive to act morally is influenced by their expectation of other members' moral behavior. The moral standards of a society are built on the outcomes of such interactions over time. We show that moral standards can quickly deteriorate even if the majority of a society's members have a strong moral value individually. When they observe that there are insufficient public moral sanctions for wrongful actions, the members come to believe that their society's moral standards are lower than what they had expected. Such a belief encourages more wrongful actions and results in less incentive for the members to act morally. As the moral standards decline, moral rules may not be able to regulate behavior. Moral standards are less likely to degenerate in the presence of legal rules as legal sanctions offer an objective and relatively time-invariant level of expectation regarding the enforcement of rules. Strong morality, in turn, enhances the effectiveness of law enforcement. We discuss a commitment value of law.