Within most countries’ emergency and disaster laws, a specific set of institutions dictates the processes of declaring an event an emergency, disaster, or calamity. Whether it occurs at the local, regional, or national level, this declaration is often a necessary first step for response and recovery processes. Yet, across countries, there is a fair amount of variance on these disaster declaration processes. In some places, decision makers are given wide discretion in deciding whether an event is a disaster. In others, the definition of disaster is circumscribed by specific criteria. This begs the question: What are the effects of these institutional differences? For example, do they contribute to increased tensions between levels of government in disaster response and recovery processes? This paper utilizes the congruence method of qualitative comparison to explore two most-similar cases, Indonesia and the Philippines, and the way disaster declaration rules affected arguments about jurisdictional responsibility in two recent volcanoes. Despite some caveats, the comparison indicates a potentially causal effect of these institutional differences and suggests a promising path of comparative research.