Introduction
In addition to conceptualizing the two types of subnational policy challenges that are examined in the book, this introductory chapter explores the distinctive possibilities and limitations of subnational neoliberalism and subnational statism as two prominent types of subnational policy regimes. It also examines the causes that have made subnational policy challenges more common around the world today and specifically within Latin America, including globalization, democratization, decentralization, party system collapse, and indigenous mobilization. Next, the chapter assesses the importance of the shift toward greater territorial heterogeneity by analyzing the possible advantages and disadvantages of this shift, including when it results in cases of policy regime juxtaposition. The chapter ends with a brief overview of the theoretical framework, which stresses the importance of structural, institutional, and coalitional factors to explain variation in the success of subnational policy challenges.