Greece, bonus seats, and PR
Greece held parliamentary elections on Sunday in which the two historic largest parties were battered at the polls while parties on the extreme right and left performed disturbingly well. The top party, New Democracy (ND) received less votes than it did in the previous election (19 percent compared to 33 percent) yet actually finished with 17 more seats than before. How did this happen?
Greece has a strange system where the party that receives the most votes gets an additional 50 seats (up from 40 during the last election) in parliament. So while there are 300 seats in the Vouli ton Ellinon, parties only really compete for 250 while the last 50 are allocated separately. The point of this, I’m assuming, is to ensure that one party or coalition has a governing majority. It obviously failed in this election as even with the bonus, ND will still just get 36 percent of all seats.
Greece’s system is a great example of how an ostensibly proportional system can perform very unproportionally. Small degrees of over-representation are consistent with most nationwide PR systems but Greece’s tends to highly exaggerate the top party while mitigating the natural bonus that we would see for the other parties. The 50 bonus seats are calculated based on the national vote total. Invalid votes are disregarded for seat allocation purposes as are votes for parties that fall below the 3 percent threshold. Therefore, we should normally expect to see most parties that enter parliament get a slightly higher percentage of seats than their raw vote total would suggest. For example, in this election, it seems all parties that entered parliament would have been over represented if you did not factor in the bonus seats (so a parliament of 250). Syriza would have received nearly 21 percent of seats for getting only 17 percent of the vote and New Democracy would have still received 23 percent for getting only 19 percent of the vote. (Figure 1) All parties, however, would have done better than their percent of the popular vote would indicate.
Figure 1 (Click to enlarge)
With the bonus, however, ND received a 17 percent boost from their raw vote total (36 percent of all seats with only 19 percent of the popular vote), while Syriza stayed at basically the same level. The other parties, however, got around a fraction of a percent less of the seat total than their popular vote would have indicated. This somewhat has the effect of awarding all wasted votes to New Democracy. That last column in Figure 1 shows how the bonus affected that party’s seat total compared to a parliament without the 50 bonus seats.
Attempting to create a governing majority has some understandable justifications, but what happens when no party can get that majority anyway? Now Greece’s system just gave a massive boost to one party, without anything to really show for it. In order for a party to win a majority of seats it would have to win approximately 39 percent of the vote, at a minimum. This was a number that was calculated prior to the election, so maybe it could be possible to stipulate that no party wins the bonus unless it reaches that level? Comments or corrections welcome.
 I was unaware of any other country that has a bonus system until a friend pointed me towards Italy, which guarantees 340 seats to the top-performing party. (This is somewhat unsettling, as I have already heard some people compare the performance of the extreme right and left in this election to famous elections in Italy and Germany. I don’t think we need to fret about fascism coming to Greece but it never hurts to reread Giovanni Sartori.)