This study introduces a new way to look at precedents in international economic law. It employs social network analysis to investigate citation data from close to 150 WTO Appellate Body Reports and 400 investment arbitration awards and decisions. The results reveal important insights. First, regardless of the institutional setup, the use of precedent develops and persists. Yet, the processes and structure of precedential development between a centralized legal regime and a decentralized one are distinct. The citation patterns suggest that a centralized legal regime is much more conducive to developing a de facto system of precedent due to its institutional structure. A decentralized legal regime needs critical junctures to establish reference points and develop a system of precedent. Second, the models of precedent based on the data explain important sources of precedential authority. The results show the precedential authority of both regimes derives from the legal concept of “like cases be treated alike” and the precedent-following norm, which results in a series of citations, rather than a single citation on an issue. The main difference in precedential development lies in the dynamic between the community of practice and its actors. Unlike the WTO Network, there are high degrees of self-interest and reciprocity in investment citations, reflecting arbitrators' needs to maintain social positions. The findings critically inform current reform efforts in both regimes that the status of previous decisions is important for jurisprudential development and requires checks and balances to readjust the use of precedent in the future.