We examine the role of spillover learning in shaping the value of exploratory versus incremental R&D. Using data from drug development, we show that novel drug candidates generate more knowledge spillovers than incremental ones. Despite being less likely to reach regulatory approval, they are...

Do large firms produce more valuable inventions, and if so, why? After confirming that large firms indeed produce more valuable inventions, we consider two possible sources: a superior ability to invent, or a superior ability to extract value from their inventions. We develop a simple model that...

How should industrial policies be directed to reduce distortions and foster economic development? We study this question in a multi-sector model with technology adoption, where the production of goods and modern technologies features rich network structures. We provide simple formulas for the...

Women's contribution to the economy has been markedly underestimated in predominantly agricultural societies, due to their widespread involvement in unpaid agricultural work. Combining data from the US Census and several early sources, we create a consistent measure of male and female employment...

To fill the knowledge gap that previous studies ignore either housing or internal urban structure and to enable better fit with important stylized facts, we construct a two-sector optimal growth model of housing where housing is produced by land and housing structure/household durables. We...

Transformative technologies like generative artificial intelligence promise to accelerate productivity growth across many sectors, but they also present new risks from potential misuse. We develop a multi-sector technology adoption model to study the optimal regulation of transformative...

This paper asks whether increasing productivity in the electricity sector can yield larger long-run GDP gains than suggested by electricity's small share of aggregate economic activity. We answer this question using a dynamic multi-sector model in which electricity is a strong complement to...

Over time and across states in the U.S., the number of firms is more closely tied to overall employment than to output per worker. In many models of firm dynamics, trade, and growth with a free entry condition, these facts imply that the costs of creating a new firm increase sharply with...