Research Proximity and Productivity: Long-Term Evidence from Agriculture∗

The spatial concentration of ideas is central to economic geography. Yet, how proximity to research affects productivity is not well studied. We use the late 19th century establishment of agricultural experiment stations in the United States to estimate the importance of proximity to research for productivity growth. Our analysis of county-level agricultural census data from 1870 to 2000 reveals three results. First, research proximity effects from permanent station opening grew for about 20 years and then subsequently declined until becoming largely absent today. Second, proximity to station-based innovations affected local farmers’ productivity for 20 to 40 years after the discovery. Third, research proximity effects remain today where stations historically focused on basic research and where nearby farmers were producing with frontier technology. Persistence in research proximity effects depend not just on research infrastructure, but also persistence in idea production and the cumulative effects of learning.