A new study by Bloomberg Economics takes one gauge with a knack of predicting ballot outcomes — the misery index, calculated by adding up the inflation and unemployment rates — and projects it forward through election day.

The result: Based on past voting patterns, President Joe Biden’s party can expect to lose 30 to 40 seats in the House and a few in the Senate too, easily wiping out razor-thin Democratic majorities.

Of course, economics is only one part of the calculation that voters make. Democrats will be hoping that anger over abortion and gun laws and the Jan. 6, 2021 attack on the US Capitol by a right-wing mob will energize their supporters.

There are lots of forecasting models, using all kinds of inputs — not just economic ones — and they’re predicting a range of outcomes. The analysis firm Inside Elections, for example, sees likely Democratic losses in the House at between 12 and 30 seats. Others indicate anything from a wash, with both parties ending up roughly where they started, to GOP gains of 45 seats or more.