# PredictIt vs Five Thirty Eight: An explanation of the differences between prediction markets and polling models

**sweissblaug**, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here)

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If you’re like me you’ve been looking at FiveThirtyEight and PredictIt election probabilities multiple times a day. Recently I’ve been focusing on some interesting disagreements in electoral outcomes at the state level. For instance; FiveThirtyEight gives Pennsylvania, Michigan, Florida, Wisconsin and Ohio at least 20% lower probability of a Trump victory than PredictIt. Why is PredictIt giving Trump a much higher chance in those states?

One theory is that FiveThirtyEight focuses on polls and who the people of the state will vote for while PredictIt focuses on which candidate will actually win the state. The difference could come down to who is in control of the state. It is possible that the governor or legislature may get to decide who wins. To explore this hypothesis I gathered the current predictions (morning of 2020-11-01) and compared the differences on which party controls which part of the state government (data found here and here).

Below is a bar chart ranked differences between PredictIt and FiveThirtyEight Trump probabilities on who controls the governor, Upper House, and Lower House.

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**sweissblaug**.

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