Expansion of Preferential Trading Arrangements

The growing number of preferential trading arrangements (PTAs) since World War II has generated substantial interest in their economic and political effects. It has also prompted interest in the factors that give rise to PTAs, but very little research has been conducted on the growth of extant PTAs. To address this shortcoming, we analyze why some arrangements expand, whereas others do not. We find strong evidence that expansion is most likely when the existing members of a PTA display a high degree of trade openness and when the size distribution of these members is fairly uniform. We also find that PTAs that add new members are likely to do so again in the near future and that, throughout the global system, PTAs tend to expand in clusters. Equally, there is some indication that the market size of a PTA affects its odds of expansion. Finally, we investigate which states join enlarging PTAs. We find that PTAs expand by taking on new members that are economically and politically similar to existing members.

二战以来，特惠贸易协定（Preferential Trading Arrangements, PTAs）的数量持续增长，引发学界对其经济与政治效应的广泛关注。这一发展态势同时催生了学界针对特惠贸易协定形成动因的研究兴趣，但针对现存特惠贸易协定扩员进程的相关研究却寥寥无几。为弥补这一研究短板，本文旨在分析为何部分特惠贸易协定能够实现扩员，而另一些则未能达成扩员目标。研究结果显示，当某一特惠贸易协定的现有成员国展现出较高的贸易开放度，且成员国的经济体量分布较为均衡时，该协定最有可能实现扩员。此外，研究还发现，已吸纳新成员国的特惠贸易协定，在未来短期内大概率会再次启动扩员进程；且从全球体系层面来看，特惠贸易协定的扩员往往呈现集群化趋势。另有迹象表明，特惠贸易协定的市场规模会对其扩员概率产生影响。最后，本文探究了哪些国家会选择加入正在扩员的特惠贸易协定，结果发现，特惠贸易协定往往会吸纳与现有成员国在经济与政治层面具有较高相似性的新成员国。