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.