"The electors shall meet in their respective states": Bias and the US Presidential Electoral College, 1960-2012

American Presidential elections are indirect, reflecting popular support for the candidates through the institution of the Electoral College to choose the President. In common with other plurality-based electoral systems, the College tends to exaggerate the apparent mandate received by the winner of the popular vote but, on occasion, can deliver victory to the second-placed candidate. Despite a sizeable literature on its operation and vagaries, however, relatively little attention has been paid to the question of systematic bias in the College: does one party receive a consistent advantage over the other from the College's operation? The paper examines the evidence for such a bias in each Presidential election since 1960. Although biases have occurred and in some cases were substantial, neither major party is a consistent beneficiary; the prime source of bias is to be found in the relative effectiveness of parties' own vote-winning strategies.