Proxies for the corporate marginal tax rate

This paper focuses on how best to measure the corporate marginal tax rate, which is an important input into financial analysis of the cost of capital, financing policy, corporate hedging, and corporate reorganizations. The results indicate that the simulated tax rate used by Shevlin (1990) and Graham (1996), although difficult to calculate, is the best available proxy for the 'true' marginal tax rate. If the simulated rate is unavailable, an easy-to-calculate trichotomous variable or the statutory marginal tax rate (which captures the progressively in the tax rate schedule) are resonable alternatives, better than most commonly used tax variables.