The survey found that Japan’s population held steady at roughly 127 million people, but there was considerable change in the populations of Japan’s prefectures, a continuation of the shift of Japan’s population away from sparsely populated, rural Japan to densely populated prefectures, particularly Tokyo and its surrounding prefectures.
If one looks at the top and bottom five prefectures in this survey, and looks at the relative numbers of LDP and DPJ candidates those prefectures send to the Diet, several things stand out.
First, the top five, with the latest growth figure (relative to the previous year), population and population density per square kilometer:
Aichi +.74 7,043,235 1,366
Tokyo +.66 12,059,237 5,514
Shiga +.61 1,342,811 334
Okinawa +.5 1,318,281 580
Kanagawa +.43 8,489,932 3,515
And the bottom (from fifth lowest growth rate to the worst):
Shimane -.77 761,499 114
Nagasaki -.83 1,516,536 371
Kochi -.86 813,980 115
Aomori -.98 1,475,635 154
Akita -1.02 1,189,215 102
In 2005, the top five growers elected a total of eighty-one LDP candidates — between constituency and block elections — and twenty-one DPJ candidates, comprising respectively 27% and 18% of each party’s caucus in the Lower House. The bottom five elected twenty-one LDP candidates and five DPJ candiates, comprising approximately 7% and 4% of each party’s caucus.
The greater weight of the densely populated, growing prefectures is by no means surprising — but among the eighty-one LDP candidates elected in the top five in the 2005 landslide, forty-two of them were elected for the first time in either 2003 or 2005. They are, in short, Koizumi’s children, beneficiaries of Koizumi’s popularity throughout Japan, helping the LDP grow outside of its traditional rural base. (Note that in the shrinking bottom five, of the twenty-one LDP candidates elected in 2005, only five were running for the first or second time.)
So the question is, what will happen to the LDP in the next election, when LDP candidates first elected due to Koizumi’s coattails face the voters again, this time with Abe instead of Koizumi at the head of the party? Will voters in growing prefectures be as eager to elect LDP candidates without a vigorous reformer at the helm of the party?
Another interesting question is at what point will the growing population disparities lead to pressure for a new round of redistricting (or even a new mechanism for redistricting).
These numbers do not suggest the LDP’s doom; it is well placed, in the short term, to contest and win in urban Japan. But over the medium to long term, can the LDP shift its policy bias away from protecting rural constituencies to legislating towards the interest of urban workers and consumers? If Koizumi couldn’t do it, is there anyone in the LDP who can?