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Journal of Political Economy Vol. 126 No. 4 2018

Growth through Heterogeneous Innovations

Ufuk Akcigit1,2; William R. Kerr1,3

1 National Bureau of Economic Research · 2 Centre for Economic Policy Research · 3 Harvard University

open access

Abstract

We build a tractable growth model in which multiproduct incumbents invest in internal innovations to improve their existing products, while new entrants and incumbents invest in external innovations to acquire new product lines. External and internal innovations generate heterogeneous innovation qualities, and firm size affects innovation incentives. We analyze how different types of innovation contribute to economic growth and the role of the firm size distribution. Our model aligns with many observed empirical regularities, and we quantify our framework with Census Bureau and patent data for US firms. Internal innovation scales moderately faster with firm size than external innovation.

DOI
10.1086/697901
Volume
126
Issue
4
Pages
1374-1443
Language
en
Sources
bibtex:phds-export.bib openalex crossref

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