The Mainichi Shimbun answers common questions readers may have about the outcome of the Oct. 22 House of Representatives election.
Question: The outcome is really surprising -- the Abe Cabinet didn't have a very high approval rate, did it?
Answer: In a Mainichi Shimbun opinion poll carried out on Sept. 26 and 27, the disapproval rate for the Cabinet was 42 percent, exceeding the approval rate at 36 percent. Even then, the reason Abe's Liberal Democratic Party (LDP) claimed victory was mainly because of the system combining single-seat constituencies with proportional representation blocs.
Under the single-seat constituency system, the candidate with the most votes wins. If there are two candidates, there is a chance for a tight race, but the ruling coalition of the LDP and Komeito coordinated their efforts to field only one candidate per constituency. This means that the more opposition party candidates that run in the same constituency, the more the opposition vote is divided among them. A divided opposition indirectly helps the ruling coalition candidate.
Q: So the LDP wasn't just simply strong?
A: Of course the LDP received the support of voters, but there is more to it. The LDP won 237 seats in single-seat constituencies out of 300 up for grabs in the 2012 lower house election and 223 out of 295 in the 2014 general election. However, when you look at the ratio of actual votes garnered by the party versus the ratio of seats won, in the 2012 election it was 43 percent of votes versus 79 percent of seats, and in 2014 it was 48 versus 76 percent. This is a special characteristic of the single-seat constituency system, and played a part in the 2009 and 2012 changes in the governing party.
Q: So in those constituencies, even one less vote can mean a loss? It seems like a waste.
A: Under the single-seat constituency system, it's impossible to avoid the large number of so-called wasted votes, because the winner takes all. That's why a system is used in 11 proportional representation blocs around the country where the candidate with the narrowest loss ratio in a single-seat constituency can instead be selected to fill a seat within the limits of how many proportional representation seats their party takes.
Q: Does that system benefit the ruling party or not?
A: Let's examine not just the approval rate for the governing Cabinet, but also for the LDP itself. Just ahead of the 2009 House of Representative election, the approval rate for the Aso Cabinet was at 20 percent, and the disapproval rate at 60 percent. The support for the LDP was also only at 20 percent, well below the approval rate of the Democratic Party of Japan (DPJ) of the time, which was 39 percent. As a result, the DPJ was able to win and take control of the government. When the largest opposition party itself has momentum, the single-seat constituency system doesn't necessarily work in favor of the ruling party. (Answers by Yusuke Mizuwaki, Political News Department)