Brexit and Power in the Council of the European Union

The exit of the United Kingdom from the European Union has had profound economic and political effects. Here, we look at a particular aspect, the power distribution in the Council of the European Union. Using the Shapley-Shubik power index, we calculate the member states' powers with and without the United Kingdom and update earlier power forecasts using the Eurostat's latest population projections. There is a remarkably sharp relation between population size and the change in power: Brexit increases the largest members' powers while decreasing the smallest ones' powers.