Download full paperWe consider an approach based on property rights mismatch to analyze conflict over radio spectrum. A mismatch occurs when the bundle of property rights created to enable social coordination fails to achieve this objective, leading to missed opportunities for productive exchange. With radio spectrum, these conflicts often result from technological changes that increase prospects (and satisfy demand for) sharing spectrum. Our focus is on how property regimes contribute to conflict as a result of mismatch, as well as how they might be resolved, for two examples of spectrum: passive and active spectrum uses and mobile services on the unlicensed band.