Thread by @GeorgePeretzQC

For electoral reform specialists, this is a problem with the German (and Scottish and Welsh) system, as explained here. Essentially, that system fills ~1/2 the seats by FPTP, and then allocates the other half (list seats) so as to achieve an overall proportional result.

https://twitter.com/HzBrandenburg/status/1437766263745490963

This is how it worked in Scotland last time: the SNP wins almost all the FPTP seats (fans of FPTP: note) but gets hardly any of the list seats, so as to bring its overall seat total to just under 50%.

But FPTP is easily capable of throwing up even madder results than that: in a multi party system, a party may win almost all the FPTP seats with ~30% of the vote, efficiently spread around, with the opposition split.

That is the forecast result in Bavaria.

Problem. The CSU will get all/almost all the FPTP seats. So ~50%. But it only got 30% of the vote - and allocating the 50% of list seats to the other parties doesn’t change that.

Brace yourselves for a German noun: Überhangmandate (overhang seats). Let’s assume Bavaria has 100 seats. The CSU won all of the 50 FPTP seats. But its share was 30%. So you add 67 extra list seats. The CSU now has 30%. Everyone happy (especially the 67 extra MPs).

As explained on the thread, the fun doesn’t stop there. Bavaria now has 167 seats instead of 100. So all other regions get equivalent top ups. Lots of happy extra MPs.

This sort of thing doesn’t happen all the time, by any means. But it can happen and it’s mighty odd when it does.

None of these problems can arise with the Irish and Northern Ireland system of STV, which doesn’t use FPTP or party lists at all.