International agreements are often understood to help governments make credible commitments to future policy by limiting their ability to renege on their promises. Renegotiations of agreements are accordingly viewed as a threat to cooperation, since renegotiations call past commitments into question. But we know little about the frequency or nature of treaty renegotiations. When are international agreements renegotiated, and what effect does renegotiation have on international cooperation? Do most renegotiations indeed aim to backtrack on past commitments? Using the topical context of the trade regime, I collect new data on international treaty revisions, covering 310 preferential trade agreements signed since the year 2000. Around a quarter of these agreements have been amended in some form, and the supermajority of amendments result not in scaled back agreements, but in deeper commitments. Survival analysis shows that ‘like-minded’ countries with a shared language and similar voting patterns at the UN General Assembly are most likely to revise their commitments. In contrast, I do not find evidence to support the view of PTA revisions as ‘backsliding’ on past commitments. The effects of revisions on trade cooperation support the more cooperative view of revisions. An error-correction model shows revisions are associated with a long-run increase in export volumes. Renegotiations are not breakdowns in international relations, but opportunities for governments to renew their commitment to cooperation.

国际协议通常被理解为通过限制政府食言的能力来帮助政府对未来政策做出可信的承诺。因此，协议的重新谈判被视为对合作的威胁，因为重新谈判使过去的承诺受到质疑。但我们对条约重新谈判的频率或性质知之甚少。国际协议何时重新谈判？重新谈判对国际合作有何影响？大多数重新谈判确实旨在背弃过去的承诺吗？结合贸易制度的主题背景，我收集了有关国际条约修订的新数据，涵盖了2000年以来签署的310个优惠贸易协定。其中约四分之一的协议进行了某种形式的修订，而绝大多数修订并没有导致协议的修订。缩减协议规模，但做出更深入的承诺。生存分析表明，在联合国大会上拥有共同语言和相似投票模式的“志同道合”国家最有可能修改其承诺。相比之下，我没有找到证据支持 PTA 修订是对过去承诺的“倒退”这一观点。修订对贸易合作的影响支持了更加合作的修订观点。误差修正模型显示，修正与出口量的长期增长相关。重新谈判并不是国际关系的破裂，而是各国政府重申合作承诺的机会。