Unjustified enrichment: surveying the landscape
Preliminary questions ‘Unjustified enrichment’. The expression is mysterious. So are the other terms in use for the same subject, ‘unjust enrichment’ and ‘restitution’. What is an enrichment and when is it unjustified? To state that something amounts to unjustified enrichment is merely a conclusion, that because the enrichment is unjustified it should be returned, restored or made over to the person properly entitled to it. That conclusion is in need of supporting normative argument. But what sort of argument? Some time ago the Roman jurist Pomponius wrote the now-famous words nam hoc natura aequum est neminem cum alterius detrimento et iniuria fieri locupletiorem , ‘by the law of nature it is right that nobody should be unjustly enriched at another's expense’. Pomponius's maxim encapsulates the key elements of enrichment liability: enrichment, which is unjust, and which is at the expense of the claimant. But it exemplifies a problem that faces modern legal systems, too: formulating the principles of a law of unjustified enrichment in a way which is clear and yet not excessively broad. There is no doubt that Pomponius's formulation is, as a matter of classical Roman law, much too broad. There were many cases in which unjustified enrichment was simply allowed to rest where it arose. A clear instance is the claim of a possessor in good faith who improved land from which he was later ejected by the true owner.
Unjust Factors or Legal Ground? Absence of Basis and the English Law of Unjust Enrichment
Traditionally, there are two main approaches to enrichment by transfer, the common law ‘unjust factors’ approach and the civilian ‘absence of basis’ approach. In the aftermath of the so-called ‘swaps cases’, Peter Birks proclaimed the dethronement of the unjust factors in the English system, said that English law has embraced a German-style absence of basis approach, and proposed a new system of unjust enrichment. This article proceeds in two steps. Firstly, it asks whether one of the two systems is superior to the other. Concluding that the ‘absence of basis’ approach may be conceptually clearer, it then argues that the English system should nonetheless be careful to adopt this approach for two reasons. First, this new approach may not be suited to neighbouring fields of law (especially contract), and secondly, unjust enrichment does not occupy the same place in the legal landscape in Germany and England, it is of a different normative quality.
Law of Restitution
This text aims to provide a concise account of the English law of restitution for the benefit of practitioners and students. While at times critical, it concentrates on the actual law and its impact on practical situations.