Financial leverage and corporate taxation: evidence from German corporate tax return data

To estimate the impact of profit taxation on the financial leverage of corporations, this study uses a pseudopanel constructed from comprehensive corporate tax return microdata for the period 1998-2001, which saw the introduction of major corporate tax reform in Germany. Financial leverage refers to the ratio of long-term debt to total capital. The endogeneity of the firm-specific marginal after-financing corporate income tax rate is controlled for by an instrumental variable approach. The instrument for the observed marginal tax rate is the counterfactual tax rate that a corporation would have faced in a particular period had there been no endogenous change, triggered by the tax reform, of its financial leverage and tax base. This counterfactual tax rate is derived from a detailed microsimulation model of the corporate sector, based on tax return microdata. The marginal tax rate has a statistically significant and relatively large positive effect on corporate leverage; for firms reporting positive profits, an increase of the marginal tax rate of 1 % would increase the financial leverage by approximately 0.7 %, on average. The debt ratio is less responsive to tax incentives for small corporations and firms facing high economic risks.