File:Global border discontinuities in soil erosion.webp

English: "a, Spatial distribution of cropland soil erosion rates (t ha−1 yr−1) within 80 km of international borders. The brown dots are 2 km long, local averages; the blue lines are fitted spatial trends. The dotted line is the average global border. All data points from countries with a higher erosion rate than their pairwise neighbour are plotted to the left of the border, whereas all data points from countries with a lower erosion rate than their pairwise neighbour are plotted to the right. A country effect is indicated by the discontinuity right at the border. b, Countries sorted according to their number of implemented soil policies. All data points from countries with more soil policies than their pairwise neighbour are plotted to the left of the border, whereas all data points from countries with fewer soil policies than their pairwise neighbour are plotted to the right. A policy effect is indicated by the discontinuity right at the border. c, Estimated coefficients (the centres of the bars) and corresponding 99%, 95% and 90% confidence intervals (the bars) from a spatial regression discontinuity design. The first three coefficients show the percentage soil erosion change that is estimated for a grid cell being in the country that causes more soil erosion compared with one being located in the neighbouring country that causes less (a–c). The last three coefficients show the percentage soil erosion change that is estimated for a grid cell being in the country that has implemented more soil policies compared with one being located in the neighbouring country that implemented fewer (d–f). (N = 15,687,325)."