The erosion of rights by past breach

Legal rights may erode as a result of past, uncontested, breach.In light of ongoing violations, the rightholder's lacklusterenforcement may result in the loss of the entitlement. The doctrinesof course of performance in contract law and adverse possessionin property law are prominent examples of this widespread erosionphenomenon. In analyzing the effects of such laws, the articleconfronts two conflicting intuitions. On the one hand, the 'licence'to continue breach prospectively encourages opportunism. Onthe other hand, the risk of erosion may reinforce the rightholder'smotivation to take antierosion measures, bolstering the credibilityof the threat to enforce, thus better preserving the entitlement.The article proves that these two effects of erosion rules alwaysbalance out. The same amount of value will be extracted fromthe rightholder, irrespective of the law's erosion doctrine.The article also demonstrates the limits of this 'irrelevance'claim and the factors that may lead to its collapse. It appliesthe analysis to offer new perspectives on various prominentlegal rules.