Making enrichment the focus of restitutionary liability is a fundamental error. It leads to an untenable prejudice against unearned gain. At the same time, it denies restitution to parties who should obtain it. Only limited interests have been, and ought to be, protected by the law of restitution. These include autonomy in the transfer of our property and in committing ourselves to binding obligations. Where the protections are triggered, restitution follows whether or not the defendant has been enriched. Expenditure of our time and effort is not (or is almost never) a protected interest, nor is our paying a third party to do things, even if others are enriched thereby. Such others need to have requested the expenditure or otherwise participated in a way that makes it just that they cover or contribute to the resulting costs—where such participation is present, enrichment is (almost always) superfluous. By buying into the concept of ‘unjust enrichment’, English courts since Banque Financière have overlooked and sometimes ignored paths of long-established precedent, and headed off into the wilderness. Bad claims have been recognised and good ones spurned. Even when the courts alight at the right place, we find judges not clearly or consistently identifying the enrichment that they say helped them get there, or we find them deeming an enrichment to have been present when they know it was not really there.
Peter G Watts, ‘Unjust Enrichment’—the Potion that Induces Well-meaning Sloppiness of Thought, Current Legal Problems (2016) doi: 10.1093/clp/cuw010. First published online: November 17, 2016.