Replication Data for: Iowa Electronic Markets: Forecasting the 2024 U.S. Presidential Election

We present Iowa Electronic Markets (IEM) forecasts for the popular vote shares in the 2024 U.S. Presidential election. We discuss the differences between IEM forecasts and polls, the impact of the first Presidential debate, the changes resulting from Biden dropping out of the race, and the degree of uncertainty implied by IEM forecasts. On September 29, the IEM forecast a 9 percentage point Democratic popular vote margin according to a thinly traded vote-share market and an 85.7% chance the Democrat will receive more votes than the Republican in a thickly traded winner-takes-all market. Using a distribution derived from both markets, the forecasts are for a 6 to 7 percentage point Democratic margin and 87.0% chance of winning.