評估跨國人口移動與全球城市經濟互動之關聯性: Multi-level ERGM 分析

Abstract

近年來，在討論全球經濟網絡議題之時城市之間的經濟互動為不可忽視的 重要因素。在過去的研究之中，諸多學者透過城市之間的旅運資料來量化 城市之間的經濟互動，例如:飛航或是鐵路。然而，多數研究僅將研究專 注在其中一種運輸模式之上，並且無法再研究資料之中捕捉「經濟」的面 相。除此之外，由於城市在議題之中扮演重要角色，多數研究忽略了其國 家在經濟網絡之中的影響力。回應以上兩個問題，本研究的研究樣區選定 美洲以及歐洲的國家以及城市。全球經濟城市網絡(World city network, WCN)被用於建立城市之間的經濟互動，而國家之間的商業人口流動則是 用於量化國家之間的連結。接著，多層指數隨機圖模型(Multi-level exponential random graph model, Multi-level ERGM)被用於解釋國家對城 市經濟互動之間的影響。從模型結果可以看到，僅有城市層級的模型以及 加入國家層級的兩個模型之間的結果顯著不同，顯示國家在網絡之中的位 置對城市之間經濟互動的形成的影響為不可忽視的，同時，模型之中的各 項結構也顯示國家層級之間的連結會影響城市層級之間的連結。本研究的 研究結論為，國家層級間的各項網絡中心性以及網絡結構，皆對城市之間 的經濟互動的形成有顯著影響。

City economic interaction has long been a popular topic when it comes to global economic networks, especially when cities start to interact with each other individually. In past studies, scholars have been quantifying the economic interactions between cities through transportation data, such as airlines or railroads. However, the previous studies mostly constrained their study to one specific transportation method and they are not able to capture the idea of ‘economic’. In addition, while cities play the one and only important role in the past study, the power of the country to the city is also neglected. To solve the two questions, cities and countries in the Americas and Europe have been chosen as the study area. The world city network (WCN) model is used to build economic network interactions between cities and the human business mobility data is used to represent the linkage between countries. Afterward, the multi-level exponential random graph model (ERGM) is applied to the model to interpret the power of countries on cities. The results show that comparing the model with only city-level, and the model with country-level added, the two model shows a completely different result, where the positions of countries have a greater impact on the city economic interaction and the morphologies in the model also shows the significant effect of the linkages between countries to cities. In other words, the power of counties over cities is significant. This study concludes that the positionality of countries and the network structure at the country level have a significant impact on the formation of economic interaction between cities.