Financial Contracts’ Comparison in Islamic Financing System and Conventional Financial System Considering Contract Enforcement Cost

Islamic financing system as an alternative to the current financial system by eliminating usury (ribā) offers alternative contracts including benevolent lending (Qardh al-hasan), contracts of exchanging and partnership contracts to solve the problem of financing in different situations. The economic literature also introduces two general categories of partnership-based procedures and debt-based as financing structures and various studies have been presented to justify the optimal debt (optimality of debt) procedure. Exchange contracts are also based on debt structure among Islamic contracts. In this article, while examining the mentioned literature and counting (considering, including) the difference between usury contracts and Islamic literature, a theoretical model based on game theory is presented with the expansion of previous studies, which in terms of the cost of contract can compare different Islamic exchange contracts with each other and with usury. In fact, its purpose is the possibility of detail between different debt creation structures and their comparison. Based on the result of this model, exchange contracts in which the ownership structure is such that the ownership of the underlying asset is at the disposal of the financier at the beginning of the contract and after fulfilling the obligations of the receiver, the property funds are transferred to him and they have priority over usurious contracts and other exchange contracts and are optimal.