Collective action problems arise when actions that are individually rational give rise to results that are collectively irrational. Scholars have used such a framework to shed light on various political phenomena such as revolutions, civil disobedience, voting, climate change, and the funding of social services. We examine their findings and probe the theoretical foundations of their approach. What does this way of thinking about politics bring into focus, and what does it leave out? What role do institutions play in resolving collective action problems? And what if the required institutions are absent? Can we, as individuals, be required to cooperate even if we expect that others may not play their part? Readings drawn from philosophy, political science, economics, and sociology.