Infrastructural Rigidity: Formal Amendment in Indonesia, the Philippines, and South Korea

Abstract

Constitutions with very different amendment rules can share the same outcome. Indonesia’s 1945 Constitution has not been formally amended since 2002, and the Philippine and South Korean Constitutions have not been amended since their adoption in 1987, although Indonesia requires only an absolute majority of its People’s Consultative Assembly and no referendum, the Philippines requires a plebiscite, and South Korea combines a two-thirds parliamentary majority with a referendum subject to a turnout quorum. Neither the difficulty of amendment rules nor the idea of amendment culture explains this convergence. A doctrinal and functional comparison of the three amendment clauses, their implementing statutes and parliamentary rules, the leading judicial decisions, and every amendment attempt that reached a formal stage between 1987 and September 2026 shows that rigidity in these systems is infrastructural rather than numerical. The decisive obstacles lie in the law through which the amendment rules are operated: in Indonesia, an unregulated procedure that cannot confine an amendment session to its stated agenda; in the Philippines, a contested voting mode and inadequate initiative legislation; and in South Korea, a referendum law that was inoperative from 2016 to 2026 and a members-in-office threshold that makes a minority boycott decisive. Part of what comparative scholarship has treated as amendment culture is a rational response to that infrastructure. The concepts of amendment infrastructure and infrastructural rigidity connect rules-based and culture-based accounts of formal amendment and support a reconstruction of Indonesia’s amendment procedure that adds predictability without lowering its thresholds or importing a referendum.