Mixed-member proportional representation

The electoral system invented for the Federal Republic of Germany and still used there, as well as in New Zealand and a few other places.

The idea is that you still divide the electorate into geographical voting areas and they vote for local representatives as in first-past-the-post, but in addition to this you run a parallel election for parties as in proportional representation. Then you have twice as many seats as constituencies and the extra seats are used to balance out the results of the local elections as according to the party election results.

In Germany there’s a 5% hurdle with an exception for parties which get 3 local seats; in New Zealand it’s the same but the exception stands for parties with only one local seat.

When used in the UK, systems like this are usually called ’additional member’ and in order to make sure that the voting system is still unfair, they typically don’t double the number of seats but instead give only 25% more. This prevent full proportionality and maintains the UK tradition of elected dictatorship instead of true democracy.