Lewis-Beck & Tien

The model by Michael Lewis-Beck and Charles Tien is a classic political economy model, which predicts the two-party popular vote from two variables that measure political popularity and economic growth.

2016 forecast

For the 2016 election, the model predicts a narrow victory for Hillary Clinton with 51.1% of the major party vote (compared to 48.9% for Donald Trump).

Vote equation

The regression model’s vote equation, estimated on data back to 1948, reads as:

V = 37.5 + 0.26 popularity + 1.17 economic growth

Calculate your own forecast

Table 1 shows the model variables and values for 2016. By adjusting the variable values in the green highlighted cells, you can see how the model forecast would change under different conditions.

Table 1: Overview of variables used in the political economy model
Variable Description 2016 value
popularity Gallup Presidential Approval measure in July of the election year
economic growth GNP growth in the first two quarters of the election year
V Incumbent share of the two-party presidential vote


Lewis-Beck, M. S. & Tien, C. (2016). The political economy model: 2016 US election forecasts. PS: Political Science & Politics, 49(4), 661-663.