We explore how firms grow by adding products. In contrast to most earlier work on the topic, our conceptual and empirical framework allows for separate treatment of product innovation (vertical differentiation) and diversification (horizontal differentiation). The market context is Japan's...

The diffusion of technological knowledge is key to industry growth. But not all knowledge is created equal. I use a nanoeconomic approach to examine knowledge-diffusion based growth in the Meiji-era Japanese cotton spinning industry, which enjoyed remarkable success after a decade of initial...

We document that since 1997, the rate of startup formation has precipitously declined for firms operated by U.S. PhD recipients in science and engineering. These are supposedly the source of some of our best new technological and business opportunities. We link this to an increasing burden of...