Economic-Comparative Analysis of the Theory of Effective Breach with Contractual Liability in Iran, French and Common Law

One of the causes of contractual liability is the breach of obligation by the obligee, after which the obligee can deal with such a breach by resorting to the guarantee of legal performance. The usual solution in Iranian and French laws is written as a law, that the absolute responsibility of the performance of the same obligation rests with the obligee and he is required to adhere to the contract in any situation; Of course, this solution in the current French law was changed after the 2016 reforms and became closer to the common law solutions. In common law, relying on the principle of  "necessity of proper gain of the contract", breaching the contract in the event that the execution of the transaction is disadvantageous due to reasons such as market fluctuations or non-execution of the contract is more beneficial than its execution, is considered a rational matter and its possibility is accepted, and despite Different procedures have been considered based on the type of violation, but it still faces the challenge of moral objections. This research, with the aim of establishing the possibility of an effective violation in Iran's legal system, uses a descriptive-analytical method to apply this theory to the pillars and certainties of this legal system and examines the objections to it, especially the forms of contradictions with ethics. The study of the systems that accept this theory shows that it is possible to consider the violation as permissible with the aim of avoiding the loss caused by the implementation, gaining more profit than the profit of the implementation, or gaining the satisfaction of the other party, it is also possible to stay away from moral objections, which is the necessity of observing the Pareto criterion. It plays a significant role in solving these problems. By proving the possibility of applying the three elements of "Substitution of the desired instead of the same", "Mitigation of Damages" and "third party responsibility" in Iran's legal system, it facilitates the acceptance of the theory of violation.