بررسی انتقادی نظریه‌های نرخ سود ارائه‌شده توسط اندیشمندان اقتصاد اسلامی

Abstract
Despite more than four decades since the enactment of the Usury-Free Banking Act in Iran, fundamental challenges persist in designing a coherent, operational, and Sharia-compliant framework for determining profit rates within the Islamic financial system. A critical review of the literature reveals that existing theories-notwithstanding their considerable diversity-suffer from several fundamental limitations.
First, a lack of comprehensiveness: many approaches focus exclusively on sector-specific or contextual issues within Iran’s economy, thereby lacking generalizability to the broader Islamic monetary system. Second, theoretical deficiencies: several theories fail to adequately incorporate macro-policy dimensions or the institutional requirements of Islamic central banking. Third, a disconnect from contemporary monetary policy literature: a significant portion of these theories overlook recent developments regarding the role of the policy rate in macroeconomic management and the guidance of expectations. Fourth, insufficient attention to the real sector: while Sharia principles emphasize linking profit rates to the real return on capital, many theories lack practical mechanisms grounded in actual economic activity.
Using a descriptive-analytical and documentary method, this article reviews and evaluates both domestic and international theories of profit-rate determination. It demonstrates that none of the existing approaches can, independently, satisfy the three foundational criteria of the Islamic financial system: Sharia compliance, linkage to the real sector, and applicability to monetary policy. The findings highlight the need for a hybrid and institutional framework that preserves Sharia principles, utilizes real-sector indicators, and enables the central bank to conduct effective monetary policy and derive a unified policy rate. The study concludes that transitioning toward such a framework requires integrating valid elements from existing theories and establishing essential institutional prerequisites, including information transparency, development of the sovereign sukuk market, and strengthening the operational mechanisms of monetary policy in Islamic central banking.