Born Different: Entrepreneurship through Inventor Mobility, Innovation, and Growth

Large productivity differences across firms reflect substantial ex-ante heterogeneity at entry, yet the origins of this heterogeneity remain poorly understood. This paper shows that innovating spinouts—firms formed by inventors leaving incumbent innovators—are a key endogenous source of high-growth entrepreneurship and aggregate productivity growth. Using inventor mobility in patent data, we document that spinouts systematically outperform other entrants throughout their life cycle, their performance is strongly linked to parent-firm technological strength, and their formation temporarily depresses parent-firm innovation. We develop a Schumpeterian growth model that endogenizes spinout formation and the fundamental tradeoff between knowledge diffusion, creative destruction, and appropriability. Closely disciplined by rich microlevel data, the model implies that spinouts account for a disproportionate share of high-growth firms and nearly forty percent of aggregate productivity growth, but that inventor departures also impose sizable costs on incumbents, generating a fundamental policy tradeoff. Policy counterfactuals show that relaxing non-compete restrictions raises aggregate growth and welfare and amplifies the effectiveness of entry subsidies.