We build a model of firm-level innovation, productivity growth and reallocation featuring endogenous entry and exit. A new and central economic force is the selection between high- and low-type firms, which differ in terms of their innovative capacity. We estimate the parameters of the model...

Does capital accumulation increase labor demand and wages? Neoclassical production functions, where capital and labor are q-complements, ensure that the answer is yes, so long as labor markets are competitive. This result critically depends on the assumption that capital accumulation does not...

In the presence of markup differences, externalities and other social considerations, the equilibrium direction of innovation can be systematically distorted. This paper builds a simple model of endogenous technology, which generalizes existing comparative static results and characterizes...

The Americans With Disabilities Act (ADA) requires employers to accommodate disabled workers and outlaws discrimination against the disabled in hiring, firing, and pay. Although the ADA was meant to increase employment of the disabled, it also increases costs for employers. The net theoretical...

This essay discusses the effect of technical change on wage inequality. I argue that the behavior of wages and returns to schooling indicates that technical change has been skill-biased during the past sixty years. Furthermore, the recent increase in inequality is most likely due to an...

I analyze an economy in which profit-maximizing firms can undertake both labor- or capital-augmenting technological improvements. In the long run, the economy looks like the standard growth model with purely labor-augmenting technical change, and the share of labor in GDP is constant. Along the...

Average schooling in US states is highly correlated with state wage levels, even after controlling for the direct effect of schooling on individual wages. We use an instrumental variables strategy to determine whether this relationship is driven by social returns to education. The instrumentals...

This paper argues that unemployment insurance increases labor productivity by encouraging workers to seek higher productivity jobs, and by encouraging firms to create those jobs. We use a quantitative general equilibrium model to investigate whether this effect is comparable in magnitude to the...

Becker's theory of human capital predicts that minimum wages should reduce training investments for affected workers, because they prevent these workers from taking wage cuts necessary to finance training. We show that when the assumption of perfectly competitive labor markets underlying this...

In this paper, I develop a model to analyze how skill premia differ over time and across countries, and use this model to study the impact of international trade on wage inequality. Skill premia are determined by technology and the relative supply of skills. An increase in the relative supply of...