Globalization and Political Structure
构建理论框架研究全球化与政治结构的互动，发现运输成本下降时政治结构先通过扩大国家规模消除边界，后通过创建国际联盟降低边界成本，导致国家规模缩小，外交取代征服成为确保市场准入的工具。
Abstract This paper develops a theoretical framework to study the interaction between globalization and political structure. We show that political structure adapts in a non-monotonic way to declining transport costs. Borders hamper trade. At an earlier stage, the political response to expanding trade opportunities consists of removing borders by increasing country size. At a later stage, instead, it consists of removing the cost of borders by creating international unions. This leads to a reduction in country size. Moreover, diplomacy replaces conquest as a tool to ensure market access. These predictions are consistent with historical evidence on trade, territorial changes, and membership of international unions.