JBS Vol 25. Num 1. 2023. Article 2 - A Bridge for Economic and Social Change in the Lagging Region - The Effects of Jamuna Bridge in Bangladesh

The effects of market integration due to investments in transport infrastructure have been the focus of a large and growing economic literature. However, most of the existing studies analyze the effects of roads and highways, as well as railways, while research on the effects of large bridges remains scarce. The Jamuna bridge, a 4.8 km bridge over the river Jamuna in Bangladesh, is a welcome exception in that it has been studied recently by a number of scholars. We provide a critical review and synthesis of this literature with an emphasis on the methodological issues. In a difference-in-differences design that aims to study the impact of a bridge, it is important to exclude the areas integrated before the bridge construction from the comparison group. The counterfactual estimated with the integrated areas as the comparison is “no river” when the correct counterfactual is “no bridge over the river”. The evidence suggests that the newly connected hinterland experienced economic revival driven by agricultural productivity growth even though the bridge caused deindustrialization. Spatial heterogeneity is important, and policies based on the average effects are likely to be counterproductive. Lower migration costs lead to work migration for rural men, but, for rural women, it leads primarily to marriage migration with rural-born migrating men earning a premium, or higher dowry, in the marriage market. These gender differences in rural-urban migration reflect the interaction of lower migration costs with gender norms.