"We argue that a firm's aggregate risk is a key determinant of whether it manages its future liquidity needs through cash reserves or bank lines of credit. Banks create liquidity for firms by pooling their idiosyncratic risks. As a result, firms with high aggregate risk find it costly to get...

Ensuring that a firm has sufficient liquidity to finance valuable projects that occur in the future is at the heart of the practice of financial management. Yet, while discussion of these issues goes back at least to Keynes (1936), a substantial literature on the ways in which firms manage...