Citizens united: a theoretical evaluation

The 2010 U.S. Supreme Court's decision on Citizens United v. FEC lifted restrictions on the funding by unions and corporations of groups engaging in independent political advertising (outside spending). Many have criticized the majority opinion's premise that outside spending cannot corrupt or distort the electoral process. Fewer have examined the implications of this decision under the Court's assumptions. Using a game-theoretic model of electoral competition, we show that informative outside spending by a group whose policy preferences are partially aligned with the electorate may reduce voter welfare. This negative effect is more likely when policy information is highly valuable for the electorate or congruence between the group and voters is high. We further show that the regulatory environment produced by the Court's decision is always suboptimal: the electorate would be better off if either groups were allowed to coordinated with candidates or if outside spending was banned altogether.