主讲人简介:

Weiwen Yin is currently an assistant professor at the Department of Government and Public Administration, University of Macau. He received his Ph.D. degree from the Department of Political Science, Texas A&M University, worked as an assistant professor at The Education University of Hong Kong, and was a postdoctoral research fellow at the Columbia-Harvard China and the World Program. He is actively researching the political economy of state building, particularly in the context of pre-modern East Asia. Additionally, his work extends to computational social sciences, such as the estimation of heterogeneous treatment effects. His publications appear in Journal of Conflict Resolution, Review of International Organizations, Political Science Research and Methods, Explorations in Economic History, among others.

Abstract:This paper examines the factors driving a country's unification and fragmentation, with a focus on pre-modern Japan as a case study. We examine two versions of the fractured land hypothesis: (1) terrain ruggedness and (2) the presence of multiple economic cores, that are said to hinder unification. Using a historical simulation approach, we apply Q-learning, a reinforcement learning algorithm, to model political evolution. The Japanese archipelago is divided into 6,000 grid units, each acting as an intelligent agent that learns optimal expansion strategies through trial and error. Our findings reveal that the existence of an economic core is critical for achieving state unification; when economic yields are uniformly distributed across agents, a larger degree of fragmentation persists. Interestingly, terrain ruggedness is found to have no significant impact on this process. These results provide new insights into the role of economic geography in state formation and highlight the nuance of topographical explanations in shaping political outcomes.