The Geography of Development
构建了一个包含真实地理特征的动态空间增长模型，量化了放松移民限制对全球福利的影响，发现完全放开移民可使福利提高约三倍。
We develop a dynamic spatial growth theory with realistic geography. We characterize the model and its balanced-growth path and propose a methodology to analyze equilibria with different levels of migration frictions. Different migration scenarios change local market size, innovation incentives, and the evolution of technology. We bring the model to the data for the whole world economy at a 1° × 1° geographic resolution. We then use the model to quantify the gains from relaxing migration restrictions. Our results indicate that fully liberalizing migration would increase welfare about threefold and would significantly affect the evolution of particular regions of the world.