1. The "weakness" of enrichment claims in German law

We have so far been looking at the requirements for liability deriving from unjustified enrichment. We must now still add a few words about the extent, or measure, of this liability.

If we turn our attention, first of all, to modern German law, we find § 812 I 1 BGB merely providing that the recipient has to make restitution of whatever he has acquired without legal ground at somebody else's expense. Obviously, if restitution in kind is impossible on account of the nature of what the recipient has acquired, he is bound to make good the value.-⁵⁷⁸ But then there is a highly significant restriction placed upon all unjustified enrichment claims: the obligation to make restitution in kind, or to restore the value, is excluded in so far as the recipient has ceased to be enriched.^[4577] Thus it is the enrichment creditor who is made to bear the risk of all events which adversely affect the economic benefit accruing to the recipient: the destruction or confiscation of the object concerned as well as, for example, the unfavourable consequences of imprudent investment decisions on the part of the recipient.^[4578] This is the characteristic "weakness" of unjustified enrichment claims in German law:^[4579] the defendant is liable only for his actual "enrichment" at the time of litispendence—of the amount, that is, by which all the advantages accruing to him from the event on which the enrichment action is based outweigh the associated or consequential disadvantages. Other modern legal systems tend to be less well disposed towards the recipient/defendant.^[4580]" What induced the German legislator to make enrichment claims so unattractive?

2.

More on the topic 1. The "weakness" of enrichment claims in German law:

1. "Solutio propria", "in praecisa forma et specie obligationis"[3885] (to use the terminology of the European ius commune) has always been, and still is, the most important way of terminating obligations.
2. 1. The "iron" rule of Roman law and the notion of an implied lex commissoria
3. Essential elements of Roman "labour law"
4. 2. The "natural" law of delict
5. Instances of "weak** enrichment liability in Rome
6. 2. From "Konsumptionskonkurrenz" to "Solutionskonkurrenz"
7. "Contributory negligence" in Roman law
8. "De facto" contracts and implied promises
9. "Quod metus causa gestum erit, ratum non habeo"
10. 1. Restoration, damages and "Dtfferenztheorie "
11. "Si paret... dare oportere"
12. "Animus iniuriandi" and Artemus Jones
13. Causa as an extra piece of "garment"
14. Unenforceable obligations ("obligationes naturales")
15. The limits of the notion of "corrumpere"
16. On the "reality" of real contracts
17. The "community of collective hand"
18. The meaning of "occidere"
19. OTHER FORMS OF "SOLUTIO IMPROPRIA"