Michael Gilbert has posted this draft on SSRN (forthcoming, Virginia Law Review).  Here is the abstract:

Sincere rules mandate behavior a rule-maker wants, while insincere rules mandate different behavior. To illustrate, if a legislator wants cars to travel at 55 miles per hour, she could adopt a sincere rule — a speed limit of 55 — or an insincere rule, such as a speed limit of 45. When enforcement is costly, rule-makers can use insincere rules to improve the behavior of regulated parties. This works through two mechanisms, one punitive and the other deceptive. The first operates when insincere rules turn minor violations of law into major ones that carry a severer sanction. To illustrate, the penalty for driving 56 miles per hour usually increases if the speed limit drops from 55 to 45. The second mechanism operates when insincere rules convey a false impression of the governing law. To illustrate, if drivers believe the “real” speed limit is 55, they may go 56, but if they believe the real limit is 45, they may go slower than 56. Insincere rules get the law in books wrong but the law in action right. They can benefit rule-makers in many circumstances, and they may permeate legal systems worldwide.