1 论文标题
Railroads and American Economic Growth: A “Market Access” Approach
2 作者信息
Dave Donaldson, Richard Hornbeck
3 出处和链接（比如，NBER working paper No.11000）
NBER Working Paper No. 19213
Issued in July 2013
4 摘要
This paper examines the historical impact of railroads on the American economy.  Expansion of the railroad network may have affected all counties directly or indirectly – an econometric challenge that arises in many empirical settings.  However, the total impact on each county is captured by changes in that county's “market access,” a reduced-form expression derived from general equilibrium trade theory.  We measure counties' market access by constructing a network database of railroads and waterways and calculating lowest-cost county-to-county freight routes.  As the railroad network expanded from 1870 to 1890, changes in market access were capitalized into county agricultural land values with an estimated elasticity of 1.1.  County-level declines in market access associated with removing all railroads in 1890 are estimated to decrease the total value of US agricultural land by 64%.  Feasible extensions to internal waterways or improvements in country roads would have mitigated 13% or 20% of the losses from removing railroads.