Mi opinión acerca de si la adquisición a non domino es más eficiente que la regla nemo ad alii transferre potest es diferente. Hay que distinguir ámbitos: en relación con bienes destinados a circular, la adquisición a non domino es más eficiente, pero, en general, la regla eficiente es la segunda. El trabajo de Paz-Ares sobre “Seguridad jurídica y seguridad del tráfico” es el primero, en lo que nos consta, que formula entre nosotros esta distinción y el que me parece más iluminador, aunque acabo de comprobar que solo cito al autor en el texto pero no en las notas, es el de Barak Medina The Owner's Interest in Only Partial Protection of her Rights toward Third Parties: The 'Market-Overt' Rule Revisited (August 15, 2001).
Different from the aforementioned solutions, under the French principle of non-cumul, a victim of breach of contract cannot pursue a tort claim concurrently; when an obligation exists by virtue of a contract, it cannot also exist in tort. As stated, the doctrine of non-cumul is a natural consequence of the definition of a tort under article 1382 of the French Civil Code: “Any act whatever of man, which causes damage to another, obliges the one by whose fault it occurred, to compensate it.” Independent of doctrinal and historical explanations, however, it is disputable that the common law rule of accumulation of contractual and non-contractual claims (also followed by some civil law jurisdictions) promotes more efficient results than the French doctrine of non-cumul.
An efficiency approach should consider obligations contracted by mutual consent over other obligations. This principle underlies both the efficient formation and efficient breach of contracts. As a general principle, the use of tort law concurrently with contract law should be limited to specific situations where, for different reasons, we suspect contractual damages are unable to achieve the correct outcome. In other words, the efficient solution should look like a general principle of non-cumulative contractual and tort obligations with some particular derogation. Those familiar with contract law around the world will immediately recognize that this general rule looks more similar to French law than to English or American or German law.
The option for a principle of non-cumul seems wise from an economic point of view. First, obligations freely negotiated should supersede potential tortious wrongdoings. Second, the possibility that breach of contract could generate a tort claim undermines efficient breach. Third, ex ante facto, a potential tort claim could deter formation of contracts or increase negotiation costs to overcome potential future tort claims. As a consequence, allowing tort claims concurrent with breach of contract claims can only be efficient in very exceptional conditions. One example is when contractual damages are unable to internalize the losses of non-performance due to externalities or the existence of serious asymmetries of information that undermine the optimality of contractual rules.
We can also consider the long-run effects of the different rules. Suppose there is an important type of breach of contract that generates significant losses of a tortious nature. If they can never be the subject of action concurrently in torts and in contracts, we expect the evolution of the law to be in such a way as to have this class included in a broader scope of contract law. Even if they are tortious in nature, the fact that they are a byproduct of a contract, and should only be cause of action in contract law, is likely to be appropriate because they are now subject to the mutual consent test. If they can be causes of action concurrently in torts and in contracts, there would be no evolutionary pressure to subject them to a mutual consent test.
In French law, where non-cumul is the rule, a large body of law has evolved under contract law over the years to extend responsabilité contractuelle to include actions that are very substantively similar to tort law. Due to the non-cumul, such rules are housed within contract law. In other words, either the legal system sticks to the non-cumul under French law and accepts the growth of responsabilité contractuelle or the system decides that these cases must be dealt with as tort law cases despite the presence of a contractual relationship.
… Our view is based on the nature of explicit mutual consent in contracts. The only exceptions should be damage situations that require high transaction costs to achieve mutual consent ex ante. Inserting these cases into a broader contractual responsibility would