With Friday’s gross domestic product report, the three economic variables that Mr. Fair has found are best at predicting elections are now in hand. They are:

–The per capita growth rate of gross domestic product in the three quarters before the elections. (Voters seem to remember recent economic history more than they do over the span of the quarter). For the first three quarters of this year, GDP per capita grew at a 1.01% annual rate.

–Inflation over the course of the entire presidential term, as measured by the GDP price index. The annual rate of inflation by this measure was 1.58%.

–The number of quarters during the presidential term that GDP per capita growth exceeded 3.2%. There has been only one such “good news” quarter — the fourth quarter of last year, when GDP per capita grew 3.3%.