美國針對性制裁中國大陸廠商的聽眾成本：訊號理論的剖析

Audience Costs, Signaling Theory, and the US Targeted Sanctions against Chinese Companies

針對性制裁的對象是企業及個人等非國家行為者，由於經濟成本與人道傷害較少，逐漸取代全面性制裁成為脅迫外交的利器。儘管國際政治經濟學界已指出針對性制裁成效差強人意，但未能說明為何美國仍持續制裁中國大陸企業，也無法解釋一度放行中興通訊等選擇性執法現象。為回答這些問題，本文根據聽眾成本理論，概念化制裁為溝通訊號，建構一個「2x3」矩陣，區分廉價、中等、昂貴訊號的層級，以及主政者傾向執法或政治化制裁的偏好差異。筆者接著採取厚資料的蒐集與詮釋途徑，檢閱美國政府各部門制裁中國大陸公司的公開聲明和執政者的回憶錄，發現美國領導人普遍具有透過制裁，產生聽眾成本以傳達守護國際秩序決心的動機。然而，川普亦有將制裁視為籌碼以換取經貿利益的政治化取向，因此削弱聽眾成本的拘束力，使得遭制裁企業獲得轉圜餘地。本研究成果補充針對性制裁在大國競爭文獻的缺口，改善聽眾成本理論分辨傳訊內容的不足，並彰顯厚資料運用於分析實施經濟國策動機的優點。

Targeted sanctions against non-state actors have become a popular coercive tool due to their lower economic costs and humanitarian consequences compared to comprehensive sanctions. Although the international political economy literature has warned of the ineffectiveness of targeted sanctions, the scholarship has yet to examine why the US continues to wield sanctions against Chinese companies. Moreover, the existing arguments fail to explain US decisions to lift bans on firms like ZTE. To solve these puzzles, I conceptualize sanctions as signals and employ the thick data approach to scrutinize policymakers’ memoirs and official statements. Specifically, this research constructs a “two-by-three” typology in which the vertical axis represents the level of audience cost and the horizontal axis denotes policymakers’ law enforcement and politicization preferences. Whereas statements made at the higher levels generate stronger hand-tying effects, policymakers’ politicization preferences undermine the credibility of targeted sanctions. Hence, American policymakers impose targeted sanctions on Chinese companies to signal commitments to international norms. Conversely, those who tend to politicize sanctions are more likely to give the green light to Chinese firms when they are able to get greater economic gains from interstate negotiations. The findings fill the gap in the literature on targeted sanctions during great power competitions, improve the explanatory power of audience cost theory, and demonstrate the analytical advantages of thick data to reveal the motivations of economic statecraft.