The Indian Ocean Region (IOR) has become one of the main economic forces globally, and countries within the IOR have attempted to promote their intra-regional trade. This study investigates the spatiotemporal evolution of the community structures of the intra-regional trade and the impact of determinant factors on the formation of trade community structures of the IOR from 1996 to 2017 using the methods of social network analysis. Trade communities are groups of countries with measurably denser intra-trade ties but with extra-trade ties that are measurably sparser among different communities. The results show that the extent of trade integration and the trade community structures of the IOR changed from strengthening between 1996 and 2014 to weakening between 2015 and 2017. The largest explanatory power of the formation of the IOR trade community structures was the IOR countries’ economic size, indicating that market remained the strongest driver. The second-largest explanatory power was geographical proximity, suggesting that countries within the IOR engaged in intra-regional trade still tended to select geographically proximate trading partners. The third- and the fourth-largest were common civilization and regional organizational memberships, respectively. This indicates that sharing a common civilization and constructing intra-regional institutional arrangements (especially open trade policies) helped the countries within the IOR strengthen their trade communities.

中文翻译：

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印度洋地区区域内贸易共同体结构的时空演变及其决定因素

印度洋地区（IOR）已成为全球主要经济力量之一，IOR内的国家已尝试促进其区域内贸易。本研究使用社会网络分析方法研究了1996年至2017年区域内贸易的社区结构的时空演变以及决定因素对IOR贸易社区结构形成的影响。贸易共同体是具有内部贸易纽带明显密集的国家集团，但在不同社区之间具有可测量的稀疏贸易纽带。结果表明，IOR的贸易整合程度和贸易共同体结构从1996年至2014年间的增强变为了2015年至2017年间的减弱。IOR贸易共同体结构形成的最大解释力是IOR国家的经济规模，这表明市场仍然是最强劲的推动力。第二大解释力是地理邻近性，这表明IOR内从事区域内贸易的国家仍然倾向于选择地理上最接近的贸易伙伴。第三大和第四大分别是共同的文明和区域组织成员。这表明，共享一个共同的文明并建立区域内的体制安排（特别是开放的贸易政策）有助于IOR内的国家加强其贸易共同体。第二大解释力是地理邻近性，这表明IOR内从事区域内贸易的国家仍然倾向于选择地理上最接近的贸易伙伴。第三大和第四大分别是共同的文明和区域组织成员。这表明，共享一个共同的文明并建立区域内的体制安排（特别是开放的贸易政策）有助于IOR内的国家加强其贸易共同体。第二大解释力是地理邻近性，这表明IOR内从事区域内贸易的国家仍然倾向于选择地理上最接近的贸易伙伴。第三大和第四大分别是共同的文明和区域组织成员。这表明，共享一个共同的文明并建立区域内的体制安排（特别是开放的贸易政策）有助于IOR内的国家加强其贸易共同体。