Time for change model

The time-for-change model, developed by Alan Abramowitz, predicts the two-party popular vote based on the state of the economy, the incumbent’s popularity, and the time the incumbent president has been in office.

Variable description

Table 1: Overview of variables used in the time-for-change model
Variable Description 2016 value
NETAPP Incumbent president’s net approval rating (approval-dis-approval) in the final Gallup Poll in June 6
G2GDP Annualized growth rate of real GDP in the second quarter of the election year 1.2
TERM1INC Presence (1) or absence (0) of a first-term incumbent in the race 0
A Constant 47.26
V Incumbent share of the two-party presidential vote  48.6

Vote equation

The model’s vote equation reads as:

V = A + 0.108 NETAPP + 0.543 Q2GDP + 4.313 TERM1INC

2016 forecast

The 2016 time-for-change model predicts a narrow victory for Donald Trump with 51.4% of the major party vote (compared to 48.6% for Hillary Clinton).

Past performance

The time-for-change model has been used to forecast U.S. presidential elections since 1992. From its first application in 1992 to 2008, the model underwent only minor changes. For forecasting the 2012 election, however, Abramowitz added POLARIZATION as a fourth variable. The following chart shows the model’s forecasts and the actual election results for each election since 1992. On average across the six elections, the time-for-change model missed the final results by only 1.7 percentage points.

References

Abramowitz, A. (2016). Will time for change mean time for Trump? PS: Political Science & Politics, 49(4), 659-660.