Measuring procedural and substantial amendment rules: an empirical exploration

Constitutional amendment difficulty or rigidity has generated extensive literature in recent times, both conceptually and empirically. Although constitutional scholars seem divided about the importance and significance of amendment limits, there has been a proliferation of indicators and statistical analysis. In this Article, while recognizing the normative debate, we provide an empirical exploration for thirty-seven countries based on factor analysis of both formal procedural rules—usually the focus of empirical work—and substantial amendment rules—which are less developed in the quantitative literature. We discuss the existing contradictions across available indicators. Implications for the literature are derived.