Human beings should live in places where they are most productive, and megacities, where information, innovation, and opportunities congregate, would be the optimal choice. Yet megacities in both China and the United States are excluding people by limiting the housing supply. Why, despite their many differences, is the same type of exclusion happening in both Chinese and U.S. megacities? Urban law and policy scholars argue that Not-In-My-Back-Yard (“NIMBY”) homeowners are taking over megacities in the U.S. and hindering housing development. They pin their hopes on an efficient growth machine that makes sure “above all, nothing gets in the way of building.” Yet the growth-dominated megacities of China demonstrate that relying on business and political elites to provide affordable housing is a false hope. Our comparative study of the homeowner-dominated megacities of the U.S. and growth-dominated megacities of China demonstrates that the origin of exclusionary megacities is not a choice between growth elites and homeowners, but the exclusionary nature of property rights. Our study reveals that megacities in the two countries share a property-centered approach, which prioritizes the maximization of existing property interests and neglects the interests of the ultimate consumers of housing, resulting in housing that is unaffordable. Giving housing consumers a voice in land use control and urban governance becomes the last resort to counteract this result. This comparative study shows that the conventional triangular framework of land use—comprising government, developers, and homeowners—is incomplete, and argues for a citizenship-based approach to urban governance.