We develop a general equilibrium model of vertical innovation in which multiple firms compete monopolistically in the quality space. The model features many firms, each of which holds the monopoly to produce a unique quality level of an otherwise homogenous good, and consumers who are...

There is now increasing evidence that for the U.S. economy, the elasticity of substitution between capital and labor, "sigma", is rising over time. To account for this, we propose a microfounded model, where the evolution of "sigma", and, hence, the shape of the aggregate production function...