US Election Forecast – 31st October 2020

Current Forecast

This is our first Forecast. From today until Polling Day we will publish each day what we think the result will be from voting on Tuesday.

With three days to go we forecast a decisive win for Biden with a Trump win unattainable. Although there is some small evidence of Trump continue to tighten the race in some States, it is not enough to pose a serious challenge to the Democrats’ hopes of regaining the White House. Unless something significant happens (or the polls are incredibly wrong), we do not expect our forecast to change much over the next few days.

Probability of Biden Winning State

Presidential Election Forecast Philosophy

Our US Presidential Election forecast is based on polling in individual states. We run a monte-carlo simulation across the entire country and then calculate the probability of each candidate winning each state or electoral district (in the case of Maine and Nebraska). From this we allocate Electoral College votes State by State giving a final total for each candidate.

Do you allocate whole States / Districts to Candidates?

As we approach Election Day, our Nowcast now moves to a full Monte Carlo simulation of the whole country. From this Nowcast onwards our seat forecast is based on allocating the total EC votes for each State / District to the candidate who “wins” in the simulation. From this we produce a probability distribution of likely outcomes.

What do you mean by Strong / Safe / Soft?

We allocate a State a grade on the following basis

Safe – 95% or greater chance of winning or all State’s EC votes allocated to one candidate in EC allocation

Strong – 70% to 95% chance of winning

Soft – 55% to 70% chance of winning

Tie – Less that 55% chance of winning for either candidate

Sites like FiveThirtyEight have a higher probability of Trump winning. What are you doing wrong?

Nothing! 538 uses a different methodology than we do and they are also producing a forecast of polling day

Can you tell me what the probability of a certain event happening is?

Sure. We provide the most interesting probabilites above, but it’s easy to calculate things like how likely Biden is to win Texas, Ohio and Florida (4.8% as of this morning). Leave a comment below if there is a particular probability you want us to share with you.