Assessing the Impact of Changing the Bank Deposit Profit Rate on Macroeconomic Variables in a Macro-structural Econometric Model

Assessing the impact of a monetary policy through the banking system on the economy is important because the highest share of Iran’s finance market belongs to the banking sector. For this purpose, this research aims to investigate the impact of changing the bank deposit profit rate through the banking system. This paper focuses on the role of deposits as one of the main financing sources of banks in a macro-structural econometric model over the period of 1973-2017.In this respect, focusing on Iran’s banking system; a model was first formulated according to the structure of the Iranian economy. Then, three scenarios, including increasing the profit rate, decreasing the profit rate, and pegging policy, were incorporated into the model to observe the impact of profit rate changes.The results of the simulation reveals a negative relationship between the deposit profit rate and gross domestic product. An increase in the bank deposit profit rate along with increasing the deposits through free credit resources raises credit provision by the banking system, causing a direct impact on investment. On the other hand, implementing this scenario increases the cost of capital and creates an inverse effect on investment. However, the impact of the cost of capital is stronger and leads to a reduction in investment and, consequently, reduces the output by 0.66%.In the scenario of decreasing the profit rate, opposite results are observed, and the output increases by 0.71%. In the third scenario (Pegging deposit profit rate to 17%), however, the output increases by 0.46%. Therefore, the results implies that an increase in the bank profit rate is not confirmed by the theory of McKinnon and Shaw and decreases the GDP.