The Geography of Unconventional Innovation

Using a newly assembled dataset of narrowly georeferenced patents, we document that innovation activity is not as concentrated in densely populated areas as commonly believed: suburban regions are responsible for a substantial share of the innovation produced. Nevertheless, high-density areas disproportionately generate innovation of unconventional nature. We provide causal evidence for a mechanism that can generate this pattern: unconventional ideas are more likely to emerge when people interact in a dense and technologically diverse environment. An endogenous growth model with heterogeneous innovation and spatial sorting reveals that optimal place-based policy in the U.S. would foster urbanization to promote unconventional ideas, at the cost of sacrificing growth and inducing higher congestion.