Since the collapse of communism the states of postcommunist Europe and Asia have defined for themselves, and have had defined for them, two primary tasks: the construction of viable market economies and the establishment of working institutions of representative democracy. The variation in political and economic outcomes in the postcommunist space makes it, without question, the most diverse "region" in the world. What explains the variation? All of the big winners of postcommunism share the trait of being geographically close to the former border of the noncommunist world. Even controlling for cultural differences, historical legacies, and paths of extrication, the spatial effect remains consistent and strong across the universe of postcommunist cases. This suggests the spatially dependent nature of the diffusion of norms, resources, and institutions that are necessary to the construction of political democracies and market economies in the postcommunist era. The authors develop and adduce evidence for the spatial dependence hypothesis, test it against rival hypotheses, and illustrate the relationships at work through three theoretically important case studies.