A preferential attachment model of campaign contributions in state legislative elections

In state legislative elections some candidates attract contributions from many donors whereas other candidates have much smaller donor pools. Why? What are the origins of these disparities? This paper conceptualizes contributions as a type of attachment between the donor and the state legislative candidate. To model the formation of these attachments, this paper proposes a variant of the Barabasi-Albert preferential attachment model. The theoretical model is tested with data on over one million contributions to state legislative candidates in 2008. The paper also derives implications for macro-level inequities across candidates which are tested by comparing the observed inequities to simulations of the preferential attachment model. The results provide strong support for the hypotheses and show that the preferential attachment model provides a parsimonious representation of contributions to state legislative candidates.