https://doi.org/10.1177/0192512118795314 International Political Science Review 2018, Vol. 39(5) 616–633 © The Author(s) 2018 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/0192512118795314 journals.sagepub.com/home/ips Informal networks and judicial decisions: Insights from the Supreme Court of the Philippines, 1986–2015 Björn Dressel Australian National University, Australia Tomoo Inoue Seikei University, Japan Abstract To what extent do informal networks shape the decisions of the Supreme Court of the Philippines? Though often raised in the Philippines, this question has never been studied empirically. To answer it, we constructed a set of social network variables to assess how informal ties, based on university connections and work affiliations, may have influenced the court’s decisions between 1986 and 2015 in 47 politically high-profile cases. Providing statistically significant evidence for the effects of political influence (presidential appointments) and hierarchical pressure (the vote of the Chief Justice) on related networks, our analysis suggests a continuing tension on the Supreme Court bench between professionalism and informality. Because the findings advance both theoretical and empirical understanding of larger issues at the intersection of courts and society throughout the region, we recommend more attention to the role of judicial networks, external to the courts as well as within them. Keywords Philippines, supreme court, judges, judicial networks, megapolitics Introduction Courts have become central players in Asia’s constitutional landscape. But despite growing aca- demic attention, there is still considerable debate about their uneven track records and whether they can be independent and neutral arbiters in political cases. Patterns of informality in Asian courts Corresponding author: Björn Dressel, Crawford School of Public Policy, ANU College of Asia & the Pacific, The Australian National University, J.G. Crawford Building No. 132 Lennox Crossing, Canberra, Australian Capital Territory 2601, Australia. Email: Bjoern.Dressel@anu.edu.au 795314IPS 0 0 10.1177/0192512118795314International Political Science ReviewDressel and Inoue research-article 2018 Article