This paper explores the interaction between human capital and innovation in the process of economic growth. Using a model of endogenous growth, we focus on how taxes and other policy instruments affect the incentives to invest in human capital. In contrast to many other growth models we find that the taxation of human capital has a substantial negative effect on its accumulation. This in turn reduces innovation and, consequently, the income growth rate. More surprisingly, other policies that are intended to stimulate growth may have opposing effects on innovation and the accumulation of human capital. For example, while subsidies to research and to intermediate inputs do have positive effects on innovation and growth, they lead to a lower stock of human capital, in the empirically relevant case when the elasticity of intertemporal substitution in consumption is low.