The Secular Decline of Bank Balance Sheet Lending

The traditional model of bank-led financial intermediation, where banks issue demandable deposits to savers and make informationally sensitive loans to borrowers, has seen a dramatic decline since 1970s. Instead, private credit is increasingly intermediated through arms-length transactions, such as securitization. This paper documents these trends, explores their causes, and discusses their implications for the financial system and regulation. We document that the balance sheet share of overall private lending has declined from 60% in 1970 to 35% in 2023, while the deposit share of savings has declined from 22% to 13%. Additionally, the share of loans as a percentage of bank assets has fallen from 70% to 55%. We develop a structural model to explore whether technological improvements in securitization, shifts in saver preferences away from deposits, and changes in implicit subsidies and costs of bank activities can explain these shifts. Declines in securitization cost account for changes in aggregate lending quantities. Savers, rather than borrowers, are the main drivers of bank balance sheet size. Implicit banks' costs and subsidies explain shifting bank balance sheet composition. Together, these forces explain the fall in the overall share of informationally sensitive bank lending in credit intermediation. We conclude by examining how these shifts impact the financial sector's sensitivity to macroprudential regulation. While raising capital requirements or liquidity requirements decreases lending in both early (1960s) and recent (2020's) scenarios, the effect is less pronounced in the later period due to the reduced role of bank balance sheets in credit intermediation. The substitution of bank balance sheet loans with debt securities in response to these policies explains why we observe only a fairly modest decline in aggregate lending despite a large contraction of bank balance sheet lending. Overall, we find that the intermediation sector has undergone significant transformation, with implications for macroprudential policy and financial regulation