This paper studies the optimal factor tax incidence in a neoclassical growth model with a given share of government expenditure in output. In the Ramsey planner's optimization, the effect of next period's capital on government expenditure equals the given share of the marginal product of capital. Capital accumulation reduces the discounted net marginal product of next period's capital by way of increasing government expenditure. In order to internalize the distortion, it is optimal to tax capital income in the long run. This article is protected by copyright. All rights reserved.