Contagion effects and ethnic contribution networks

Many political behavior theories explicitly incorporate the idea that context matters in politics. Nonetheless, the concept of spatial dependence - in particular, that behavior in geographic units is somehow related to and affected by behavior in neighboring areas - is not extensively explored. The study of campaign finance is no exception. Research in this area concentrates on the attributes of the individual donor, leaving context underexplored. Concepts such as contribution networks, for instance, are not rigorously tested. This article reexamines the impact of conventional socio-demographic covariates on campaign donation behavior by ethnic contributors and explicitly models spatial effects. The spatial analysis reveals that patterns of campaign donations are geographically clustered (exhibiting both spatial dependence, implying a neighborhood effect, and spatial heterogeneity, implying a regional effect), and that this clustering cannot be explained completely by socioeconomic and demographic variables. While socio-demographic characteristics are important components of the dynamic underlying campaign contributions, there is also evidence consistent with a contagion effect whereby ethnic contribution networks are fueling funds to candidate coffers.