Try our new Electoral Reform tool
London Polling Error Analysis
Click the button below to run 1000 simulations of the London Assembly election using randomised vote shares centred around the current polling average. It applies a layer of variation by tweaking every party's swing in every constituency based on local factors, including whether it is east or west, north or south, inner or outer London, and the local income level.
We use the Monte Carlo method to demonstrate the degree of uncertainty that's inevitable in election projections and show how even small polling errors, and local factors can lead to significantly different outcomes. In many cases the difference between an excellent year for a party and a terrible year is well within a normal polling error.
Click the button below to run the analysis. Results are calculated using the latest polling data.
The same analysis for Scotland, Northern Ireland and Wales is also available.
Current Polling Average
Constituency
List
Most simulations fall within 3% of the polling average for each party to simulate historic errors. Each simulation randomly reweights the pollsters, varies each party's vote share, and adds a little independent variation to each constituency on top of the national swing.