Nature or Nurture? Judicial Lawmaking in the European Court of Justice and the Andean Tribunal of Justice
Are international courts power-seeking by nature, expanding the reach and scope of international rules and their own authority where permissive conditions allow? Or, does expansionist lawmaking require special nurturing? We investigate the relative influences of nature versus nurture by comparing expansionist lawmaking in the European Court of Justice (ECJ) and the Andean Tribunal of Justice (ATJ), the ECJ’s jurisdictional clone and the third most active IC. We argue that international judges are more likely to become expansive lawmakers where they are supported by sub-state interlocutors and compliance constituencies, including government officials, advocacy networks, national judges, and administrative agencies. This comparison of two structurally identical international courts calls into question prevailing explanations of ECJ lawmaking, and it suggests that prevailing scholarship puts too much emphasis on self-interested power seeking of judges, the importance of regime design features, and the preferences of governments in explaining IC lawmaking.