Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We present a model where special interest groups condition contributions on the receiving candidate's support and also her opponent's. This allows interest groups to obtain support from contributions as well as from threats of contributing. Out-of-equilibrium contributions help explain the missing money puzzle. Our framework contradicts standard models in predicting that interest groups give to only one side of a race. We also predict that special interest groups will mainly target lopsided winners, whereas general interest groups will contribute mainly to candidates in close races. We verify these predictions in FEC data for US House elections from 1984-1990. (JEL D72)