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.

本文呈现了爱荷华电子市场（Iowa Electronic Markets, IEM）对2024年美国总统选举普选票份额的预测结果。我们讨论了IEM预测与民意调查之间的差异、首次总统辩论的影响、拜登退出竞选所引发的变化，以及IEM预测所隐含的不确定性程度。9月29日，根据交易清淡的票份额市场数据，IEM预测民主党普选票优势为9个百分点；而在交易活跃的赢者通吃市场中，民主党获得比共和党更多选票的概率为85.7%。利用从两个市场中推导得出的分布，综合预测结果显示民主党将领先6至7个百分点，且获胜概率为87.0%。