The role of geographic distance and technological complexity in U.S. interregional co-patenting over almost two centuries
研究了1836年至2010年美国跨区域合作专利中地理距离的影响，发现距离仍重要，且技术复杂性对距离敏感性的作用随时间反转。
This paper examines how geographical proximity affected interregional co-patenting links in various technologies in the USA from 1836 to 2010. We classify technologies by their complexity and test whether it moderates the impact of distance on collaboration. Contrary to the ‘death of distance’ hypothesis, distance still matters for knowledge creation and exchange. Moreover, we show that the role of complexity has changed over time. In the 19th century, interregional collaborations within complex technologies were more sensitive to distance than within simple ones. This pattern reversed in the late 20th century, and such collaborative relations became more resilient to distance than simple ones.