This paper uses insights from new economic geography (NEG) to examine eight commodities that span the COVID-19 medical value chain from 2000 to 2020 based on the multilayer network approach. Such an approach is distinguished from single layer approaches by taking into consideration interlayer connections. Centrality measures are based on the HITs algorithm to identify dominant exporters (hubs) and importers (authorities). We further examine the determinants of the multilayer trade networks with a gravity model. Three results are reported. First, the core-periphery structure under NEG has weakened over time with the internationalization of production in certain Covid medical commodities (CMCs). Second, home market effect remains relatively strong over time reflecting the role of NEG’s agglomeration economies in locations with large home market demand. Finally, countries that restricted certain CMCs (especially PPEs and masks) even as they simultaneously facilitated the imports of other CMCs saw a decrease in exports.

本文利用新经济地理学 (NEG) 的见解，基于多层网络方法，研究了 2000 年至 2020 年跨越 COVID-19 医疗价值链的八种商品。这种方法与单层方法的区别在于考虑了层间连接。中心性度量基于 HIT 算法来识别主要出口商（中心）和进口商（当局）。我们用引力模型进一步研究多层贸易网络的决定因素。报告了三个结果。首先，随着某些新冠医疗商品（CMC）生产的国际化，NEG 下的核心-外围结构随着时间的推移而减弱。其次，随着时间的推移，国内市场效应仍然相对较强，反映出NEG集聚经济在国内市场需求较大的地区的作用。最后，限制某些 CMC（特别是个人防护用品和口罩）的国家，即使同时为其他 CMC 的进口提供便利，也会导致出口下降。