Being a good neighbor is paramount because these men depend upon one another in myriad ways. Ellickson turns to both a law and economics approach and particularly to game theory to elaborate his theory. Ellickson defines deadweight costs as those greater than the optimal, cooperative solution in a two-person game. He then argues that in almost every instance the employment of informal norms reaches such an outcome. One of the virtues of Ellickson's approach is that he disaggregates the concept of norms into five kinds of rules.
Substantive rules define what conduct is to be rewarded or punished.
Remedial rules set out whether reward or punishment is to be applied and what sorts will be employed. Procedural rules determine how those who impose sanctions will gather information and weigh it. Constitutive rules establish the internal struc- tures of the governors of the system. Distinct calculations govern the invocation of each set of rules. Ellickson fills his book with fascinating detail about disputing practices together with clearly written expositions of game theoretical models.