Domestic Geography

Innovation activity is not evenly distributed across geographic space. Within the United States, a small number of states and metropolitan areas account for the majority of patent output. This chapter examines the domestic geography of innovation at both the state and city levels, including cumulative rankings, technology specialization profiles, temporal trends, and regional quality metrics.

The concentration documented here is consistent with agglomeration mechanisms proposed in the literature (e.g., Marshall 1890; Krugman 1991), where the co-location of technology firms, research universities, and venture capital in a small number of innovation ecosystems may generate self-reinforcing dynamics. These patterns of geographic clustering have strengthened rather than diminished over the digital era, suggesting that agglomeration forces continue to shape the geography of innovation despite advances in remote collaboration.

Within the United States, patent activity concentrates in a small number of states and metropolitan areas. The following sections examine this domestic geography at the state level, including cumulative rankings and technology specialization patterns.

California, home to Silicon Valley, accounts for more US patents than any other state, leading by a substantial margin. Texas, New York, Massachusetts, and Michigan round out the top five. This concentration reflects the co-location of technology companies and research universities in regions of concentrated inventive activity.

Beyond patent volume, locations differ systematically in the quality characteristics of their patent output. The following charts compare the top locations across four quality dimensions over time, revealing how regional innovation ecosystems produce patents with distinctive quality profiles. Use the toggle to switch between state-level and city-level views.

Moving from the state level to the city level reveals even more pronounced concentration patterns. The following analyses examine city-level rankings, the geographic diffusion of emerging technologies across metropolitan areas, and the distinctive specialization profiles that characterize individual cities.

At the city level, geographic concentration is more pronounced still. A small number of technology hubs — San Jose, San Diego, Austin, San Francisco, and Houston — account for the largest shares of patent output. These cities have maintained their leading positions for decades, suggesting that geographic clustering in innovation exhibits strong path dependence.

The Location Quotient (LQ) measures a city's relative specialization in a given technology area: an LQ above 1 indicates that the city accounts for a higher share of that technology than the national average. Elevated LQ values indicate distinctive innovation ecosystems with pronounced comparative advantages.

Drilling below the city level to US counties reveals even finer-grained concentration patterns. County-level data capture the precise administrative geographies in which patent activity clusters, highlighting the dominance of a small number of technology-intensive counties in overall US patent output.

The state-level and city-level patterns documented here reveal pronounced geographic concentration and distinctive technology specialization across the United States. The next chapter, International Geography, extends this analysis across national borders, examining how foreign filings and international inventor mobility have shaped the US patent system into a globally interconnected institution.