To give or not to give: Modeling individuals' contribution decisions

Employing data from a recent national survey on campaign finance, we examine the contribution behavior of individual citizens in the 2000 election. By disaggregating types of contributions, our model enables us to observe potential heterogeneity in the determinants of giving money to parties and candidates. We find that for both types of contributions, the effects of informational resources and solicitation on the decision to contribute outweigh those of financial resources. In addition, we propose both a theoretical and empirical distinction between the selection effects of solicitation and the stimulus effects of solicitation. By distinguishing between these dual dimensions of solicitation, our analysis provides new insight into the causal linkages between income, solicitation, and contributions. We find that while solicitation increases the likelihood of contributing through selective targeting or rational prospecting, it also does so through a stimulus mechanism.