The October 2008 issue of PS published a symposium
of presidential and congressional forecasts made in the summer
leading up to the election. This article is an assessment of the
accuracy of their models.
In summer 2008, our Jobs Model forecast a Democratic presidential
candidate two-party popular vote share of 56.6%, which would deliver
the incumbent party the biggest defeat of any post-World War II
contest (Lewis-Beck and Tien 2008). However, we argued, from our analysis of
different experimental and observational evidence, that this
unprecedented victory would be prevented by racially intolerant
voters. We estimated the net racial cost of being a black candidate
and corrected our overall forecast downward to 50.1% for Barack
Obama. The unparalleled economic crisis, initiated after the release
of our summer forecasts, prompted a reconsideration; the unique
shock to the economy was no ordinary campaign perturbation. We
calculated that the ensuing boost to anti-incumbent economic voting
would add approximately two percentage points to the opposition;
therefore, we issued a public revision of our forecast to 52.0 % for
Obama (Lewis-Beck 2008).
We are pleased that this final forecast fell so close to the actual
result of 53.5%. Nevertheless, we contend the actual result should
have been much closer to our original forecast. Given the dismal
state of the polity and the economy prior to the election, the Obama
victory should have been much bigger, as we show below.