Variables;"Model 1";"Model 2";"Model 3";"Model 4";"Model 5";"Model 6" "Versts of railroad in 1894";"0.003*** (0.001)";"0.002* (0.001)";"0.002* (0.001)";"0.002* (0.001)";"0.002* (0.001)";"0.0003 (0.001)" "Blackearth region";;"2.812*** (0.574)";"2.925*** (0.589)";"2.397*** (0.494)";"2.372*** (0.497)";"1.137 (1.098)" "Versts of railroad in 1894 × Blackearth region";;;;;;"0.002 (0.001)" "Grain yield (poods per desiatina)";;;"0.040 (0.030)";"0.025 (0.022)";"0.025 (0.023)";"0.021 (0.023)" "% arable of all land";;;;"0.043*** (0.012)";"0.043*** (0.012)";"0.043*** (0.012)" "Number of workers in production per 1,000 citizens";;;;;"–0.001 (0.006)";"–0.001 (0.006)" Constant;"2.199*** (0.533)";"1.225** (0.547)";"–0.544 (1.397)";"–1.061 (1.088)";"–0.989 (1.131)";"–0.166 (1.286)" ;;;;;; Observations;50;50;50;50;50;50 R-squared;0.162;0.460;0.475;0.560;0.561;0.578