FORECASTING PRESIDENTIAL ELECTIONS . N. R. Miller POLI 423. Forecasting Election Outcomes. Let us consider how — and how accurately and how far in advance — the outcome of Presidential elections can be predicted. We need to distinguish between
N. R. Miller
The predictive models constructed by Abramowitz, Fair, Lewis-Beck, and others all use information concerning (i) the performance of the economy and (ii) the popularity of the incumbent President (and perhaps other information) that is available long before the election in order to predict the percent of the popular vote received by the Presidential candidate of the party the controls the White House. (The models differ with respect to the exact measures of economic performance and Presidential popularity that are used and with respect to what other variables [if any] are also used.) Attached you will find data for economic performance and Presidential popularity for each Presidential election from 1948 through 2008, as well as the percent of the popular vote received by the incumbent party’s Presidential candidate for 1948-2008. Also find and fill in the data for “Streak” and “Electoral Votes.” Can you devise some kind of rule or formula based on this data to predict the percent of the popular vote won by the incumbent party candidate? According to your rule or formula, is President Obama likely to be re-elected?
YEAR were held today, who would you vote for?” is the Presidential election year.
INC is 1 if the incumbent President is running for re-election; 0 if “open-seat” election.
GDP is real annualized GDP growth over the Fall, Winter, and Spring quarter preceding the election (e.g., from October 1, 2011 through June 30, 2012 (from U.S. Department of Commerce, Bureau of Economic Analysis, http://www.bea.gov/national/index.htm#gdp).
UNEMP is the Unemployment Rate in July preceding the election (from U.S. Department of Labor, Bureau of Labor Statistics, http://data.bls.gov/timeseries/LNS14000000).
ΔUN is the change in the Unemployment Rate from July of the year preceding the election to July of the election year.
STRK is “streak,” i.e., the number of consecutive elections won by the incumbent party
PRES is the incumbent President’s approval rating in the first Gallup Poll taken after June 30 of the election year (Gallup Reports and http://www.gallup.com/).
PV is the percent of the two-party (i.e., excluding Perot, Nader, etc.) popular vote won by the incumbent party candidate.
EV is the number of electoral votes won by the incumbent party candidate (including “faithless electors”). The total number of electoral votes was 531 prior to 1960, 537 in 1960, and 538 since 1960
* 39 electoral votes were cast for States Rights Democrat candidate J. Strom Thurmond
** 14 “unpledged” electoral votes were cast for Harry F. Byrd.
*** 45 electoral votes were cast for American Independent Party candidate George C. Wallace.
PV = 36.13 + 0.467 x GDP + 0.298 x PRES
R² = 0.736; Adj. R² = 0.695
2012: PV = 36.13 + 0.467 x 2.6 + 0.298 x 47 = 51.35
PV = 35.48 + 0.439 x GDP + 0.278 x PRES + 2.48 x INC
R² = 0.792; Adj. R² = 0.740
2012: PV = 35.48 + 0.439 x 2.6 + 0.278 x 47 + 2.74 = 52.42
PV = 36.12 + 0.337 x PRES 2012: 51.96
PV = 47.45 + 1.18 x GDP 2012: PV = 52.52
Political ScientistPredicted Obama Vote
Brad Lockerbie 58%
Thomas Holbrook 55.5%
Alan Abramowitz 54.3%
Christopher Wlezien 52.2%
Alfred Cuzan 51.9%
Helmut Norpoth 50.1%
Michael Lewis-Beck 50.07%
James Campbell Wait till Labor Day
Department of Commerce has revised second-quarter growth from 1.9% to 3.3%
PV = 47.3 + (.107*NETAPP) + (.541*Q2GDP) + (4.4*TERM1INC)
PV = 46.9 + (.105*NETAPP) + (.635*Q2GDP) + (5.22*TERM1INC) – (2.76*POLARIZATION)