Dispute settlement mechanisms in international trade vary dramatically from one agreement to another. Some mechanisms are highly legalistic, with standing tribunals that resemble national courts in their powers and procedures. Others are diplomatic, requiring only that the disputing countries make a good-faith effort to resolve their differences through consultations. In this article I seek to account for the tremendous variation in institutional design across a set of more than sixty post-1957 regional trade pacts. In contrast to accounts that emphasize the transaction costs of collective action or the functional requirements of deep integration, I find that the level of legalism in each agreement is strongly related to the level of economic asymmetry, in interaction with the proposed depth of liberalization, among member countries.
