discriminate between import-competing domestic firms and all foreign producers of the disputed products, implying that other, non-complainant trading partners also face the same policy. On the other hand, ‘partial’ policies – such as application of a WTO-inconsistent antidumping or countervailing duty or preference scheme – also discriminate between different foreign producers. In these disputes, some trading partners do not face the policy and may benefit from it being imposed on foreign peers, resulting in economic interests that are more in line with the respondent than the complainant.

Our second contribution is to provide an empirical approach that is simple and transparent. It can be easily replicated, refined, extended and used in other applications. An important goal of this work is to provide a characterization of observed trade patterns that might motivate its inclusion in future theoretically-motivated research. However, so as to make the source of our results clear, we generally refrain from imposing onto the analysis any particular modeling structure or additional set of assumptions. We establish facts based on both summary statistics and information from the full distribution of the disputed product trade data arising under the useable WTO caseload. And while we provide potential explanations for observed patterns in order to motivate avenues for additional research, for the most part we use only basic economic theory to interpret our results.<sup>1</sup> Our formal analysis allows us to report the market access characteristics of nearly three-quarters of all WTO disputes initiated between 1995 and 2011. We focus on disputes that allege WTO-inconsistent market access policies that affect product-level imports and find that WTO dispute settlement proceedings scrutinized nearly $1 trillion in imports over this period. This works out to an average of $55 billion per year, or roughly 0.5 percent of the level of world imports in 2011. Furthermore, of the subsample of WTO member challenges to import-restricting policies, we find that more the three quarters of the disputes can be linked to observed policy changes. This suggests that complainants are typically concerned with the restoration of lost market access. In the aggregate for these disputes, and without controlling for other factors that are also likely to impact trade flows, imports in the disputed products turn out to be $60 billion less in the year after the disputed policy change relative to their levels in the year prior to the change. Combined, these two sets of aggregated statistics suggest there are economically meaningful trade and market access interests _directly_ at stake in WTO disputes. And these measures do not even attempt to consider the many undoubtedly important _indirect_ market access implications of WTO jurisprudence and the resulting ‘shadow of the law.’

> 1 We do not examine any data on outcomes of WTO dispute settlement, and our comparisons are drawn only from the product markets that are subject to actual WTO disputes. Therefore, we limit our discussion to what can be learned from such an exercise, and we deliberately attempt not to extrapolate from our results to inform understanding of policies imposed by WTO members that have gone unchallenged by formal dispute settlement.

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