New technology, better economy? The heterogeneous impact of colonial railroads in Nigeria

This article documents average and heterogeneous impacts of colonial railways in Nigeria. Railways increased economic development in the short-term, in particular in areas with low pre-railway access to ports of export, including most of the North of the country. These effects persist today, despite railways no longer functioning. Conversely, railways had neither short- nor long-term effects in the South, where pre-railway access to ports of export was large, and where railways were adopted at very low rates because they were less affordable than roads and rivers. We use straight line instruments, placebo lines, and other robustness checks to rule out several alternative hypotheses for the uncovered heterogeneity. In particular, our findings are not driven by pre-railway levels of economic development, the presence of major roads, missionary activity, the timing of railway construction, differential spillovers, or the crude oil production.