This paper examines the impact of bank regulations, market structure, and national institutions on bank net interest margins and overhead costs using data on over 1,400 banks across 72 countries while controlling for bank-specific characteristics. The data indicate that tighter regulations on bank entry and activities increase the cost of financial intermediation. Inflation also has a robust, positive impact on bank margins and overhead costs. While concentration is positively associated with net interest margins, this relationship disappears when controlling for regulatory impediments to competition and inflation. Bank regulations become insignificant when controlling for national indicators of economic freedom or property rights protection, while these institutional indicators robustly explain cross-bank net interest margins and overhead expenditures. Thus, bank regulations cannot be viewed in isolation; they reflect broader national approaches to private property and competition. The paper uses two dependent variables to measure the cost of financial intermediation: the net interest margin and overhead expenditures. The net interest margin measures the gap between what the bank pays savers and what it receives from borrowers, while overhead expenditures reflect the bank's operational efficiency and competitive nature. The study finds that tighter regulations, higher inflation, and less economic freedom are associated with higher net interest margins. Bank concentration is positively related to net interest margins, but this relationship disappears when controlling for regulatory restrictions and inflation. Institutional indicators such as property rights protection and economic freedom are robustly associated with net interest margins and overhead expenditures. The results suggest that bank regulations reflect broader national approaches to competition and property rights, and that institutional factors play a significant role in shaping the cost of financial intermediation. The study also finds that macroeconomic factors such as inflation and economic growth have a significant impact on bank margins. Overall, the findings highlight the importance of institutional factors in shaping the cost of financial intermediation and the need to consider these factors when assessing the impact of bank regulations and market structure.This paper examines the impact of bank regulations, market structure, and national institutions on bank net interest margins and overhead costs using data on over 1,400 banks across 72 countries while controlling for bank-specific characteristics. The data indicate that tighter regulations on bank entry and activities increase the cost of financial intermediation. Inflation also has a robust, positive impact on bank margins and overhead costs. While concentration is positively associated with net interest margins, this relationship disappears when controlling for regulatory impediments to competition and inflation. Bank regulations become insignificant when controlling for national indicators of economic freedom or property rights protection, while these institutional indicators robustly explain cross-bank net interest margins and overhead expenditures. Thus, bank regulations cannot be viewed in isolation; they reflect broader national approaches to private property and competition. The paper uses two dependent variables to measure the cost of financial intermediation: the net interest margin and overhead expenditures. The net interest margin measures the gap between what the bank pays savers and what it receives from borrowers, while overhead expenditures reflect the bank's operational efficiency and competitive nature. The study finds that tighter regulations, higher inflation, and less economic freedom are associated with higher net interest margins. Bank concentration is positively related to net interest margins, but this relationship disappears when controlling for regulatory restrictions and inflation. Institutional indicators such as property rights protection and economic freedom are robustly associated with net interest margins and overhead expenditures. The results suggest that bank regulations reflect broader national approaches to competition and property rights, and that institutional factors play a significant role in shaping the cost of financial intermediation. The study also finds that macroeconomic factors such as inflation and economic growth have a significant impact on bank margins. Overall, the findings highlight the importance of institutional factors in shaping the cost of financial intermediation and the need to consider these factors when assessing the impact of bank regulations and market structure.