Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We use the late nineteenth-century establishment of agricultural experiment stations at preexisting land-grant colleges across the United States to estimate the importance of proximity to research for productivity growth. Our analysis reveals that proximity to newly opened permanent stations affected land productivity for about 20 years and then subsequently declined until becoming largely absent today. We conclude that spatial frictions substantially reduced the rate of return to public research spending in the late nineteenth and early twentieth centuries, but such frictions significantly diminished as extension programs, automobiles, and telephones made it easier for discoveries to reach farther farms.