Companies face different effective marginal tax rates on their income. This can be detrimental to allocative efficiency unless taxes offset other distortions in the economy. This paper estimates the effect of tax rate heterogeneity on aggregate productivity in distorted economies with multiple frictions. Using firm-level balance-sheet data and estimates of marginal tax rates, we find that tax heterogeneity reduces total factor productivity by about 3 percent. Our findings highlight the positive correlation between marginal tax rates and other distortions to capital and especially labor. This implies that tax rate heterogeneity exacerbates the distortionary effects of other frictions in the economy.
We document a strong empirical connection between corporate taxation and the manufacturing labor share, both in the US and across OECD countries. Our estimates associate 30 percent to 60 percent of the observed decline in labor shares with the fall in corporate taxation. Using an equilibrium model of an industry where firms differ in their capital intensities, we show that lower corporate tax rates reduce the labor share by raising the market share of capital-intensive firms. The tax elasticity of the labor share depends on the joint distribution of labor intensities and value added at the micro level. Given the empirical distribution in the US manufacturing sector, our quantitative analysis suggests that corporate tax cuts explain a significant part of the decline in the manufacturing labor share since the 1950s. The shift away from traditionally large, labor-intensive production units raised the concentration of market shares and reduced the concentration of employment.