계약채무불이행책임으로서 급부감축권에 대한 소고

Recognition of the right to reduce benefits is in line with the trend of modern contract liability, which is the diversification of remedies. The right to reduce benefits becomes an effective remedy for creditors as a unique effect of defective performance. And the right to reduce benefits realizes private autonomy by passively guaranteeing the binding force of contract through the guarantee of the continuity of a paid contract in general. It is a more effective remedy for the parties than the cancellation of the contract by allowing the contractual relationship to be restored and maintained by the simple method of proportional adjustment of the equivalence of a paid contract. Whether the right to reduce benefits can be recognized as a medium through the right to reduce price, which is the content of security liability, according to Article 567 of the Civil Code, must be judged differently depending on the profit situation. Even if the interpretation of Article 580 of the Civil Code is followed, recognizing the right to reduce benefits through damages in the nature of reduce price violates the principle of monetary damages under the Civil Code. The right to reduce benefits can be recognized as the effect of non-performance of contract obligations due to defective performance based on the equivalence relationship of a paid contract and the binding force of contract, and there is no reason to treat the recognition differently depending on the type of the defect or the time of existence of the defect. However, it is reasonable to recognize Article 544 of the Civil Code as a general basis because it causes effects such as partial cancellation as a formation right, which is a unique effect of defective performance under a paid contract, and partial benefits that have been incompletely performed can be treated like delayed performance. As a legislative theory, the right to reduce benefits is a unique effect of non-performance of contract obligations due to defective performance in a paid contract, but does not require the debtor's fault. Therefore, even if the performance of the obligation is partially impossible due to reasons not attributable to both parties, the creditor shall deal with it by reducing the obligation to pay in return to the extent that it is not liable. Taking this into consideration, the right to reduce benefits can be stipulated following Article 537 in the ‘Sub-Section 2. Effect of Contract’. Furthermore, by stipulating that the above-mentioned the right to reduce benefits right is applied mutatis mutandis in the seller's security liability, it can act as a basis for the unified discipline of contract liability. In this case, the case where the creditor has not paid the price and the case where the payment has already been made are separately stipulated, while the case where a notice for a reasonable period is unnecessary is specified, and the provision of the right to reduce price are applied mutatis mutandis to the case where the creditor bears non-monetary obligations.