Spatial effects and party nationalization: The geography of partisan support in Mexico

Nationalization captures the degree to which parties receive similar vote shares throughout the national territory, and is therefore explicitly interested in spatial aspects of party competition. This paper draws on spatial econometrics to analyze how parties compete across space. On the basis of a geo-referenced dataset of support for three major Mexican parties during the 2012 election, the analysis examines why there are spatial patterns of party support beyond what would be expected on the basis of district composition. The paper shows that spatial context has an independent effect on cross-district party performance, and that party support in one district increases the likelihood of party support nearby, thus highlighting why more explicit attention to space is important to understand the origins of nationalization.