They develop a structural model with investment, debt, and equity. Debt is fiscally advantageous but subject to a no-default borrowing constraint. Equity allows the firm to suspend dividends when the cash flow is negative. Firms accumulate financial assets for precautionary reasons, yet value equity as partial insurance against shocks. The calibrated model replicates the prevalence of net savings in the period 2000-2007 and attributes the rise in corporate savings over the past 40 years to lower dividend taxes.
The Macroeconomics of Firms' Savings
WP 12-1 - The authors document that the U.S. non-financial corporate sector became a net lender in the 2000s, using aggregate and firm-level data.