Japanese Elections - Malapportionment

Malapportionment

In the 1980s, apportionment of electoral districts still reflected the distribution of the population in the years following World War II, when only one-third of the people lived in urban areas and two thirds lived in rural areas. In the next forty-five years, the population became more than three-quarters urban, as people deserted rural communities to seek economic opportunities in Tokyo and other large cities. The lack of reapportionment led to a serious underrepresentation of urban voters. Urban districts in the House of Representatives were increased by five in 1964, bringing nineteen new representatives to the lower house; in 1975 six more urban districts were established, with a total of twenty new representatives allocated to them and to other urban districts. Yet great inequities remained between urban and rural voters.

In the early 1980s, as many as five times the votes were needed to elect a representative from an urban district compared with those needed for a rural district. Similar disparities existed in the prefectural constituencies of the House of Councillors. The Supreme Court had ruled on several occasions that the imbalance violated the constitutional principle of one person-one vote. The Supreme Court mandated the addition of eight representatives to urban districts and the removal of seven from rural districts in 1986. Several lower house districts' boundaries were redrawn. Yet the disparity was still as much as three urban votes to one rural vote.

After the 1986 change, the average number of persons per lower house representative was 236,424. However, the figure varied from 427,761 persons per representative in the fourth district of Kanagawa Prefecture, which contains the large city of Yokohama, to 142,932 persons in the third district of largely rural and mountainous Nagano Prefecture.

The 1993 reform government under Hosokawa Morihiro introduce a new electoral system whereby 200 members (reduced to 180 beginning with the 2000 election) are elected by proportional representation in multi-member districts or "blocs" while 300 are elected from single-candidate districts.

Still, according to the October 6, 2006 issue of the Japanese newspaper Daily Yomiuri, "the Supreme Court followed legal precedent in ruling Wednesday that the House of Councillors election in 2004 was held in a constitutionally sound way despite a 5.13-fold disparity in the weight of votes between the nation's most densely and most sparsely populated electoral districts".

The 2009 general House of Representatives election was the first unconstitutional lower house election under the current electoral system introduced in 1994 (parallel voting and "small" FPTP single-member electoral districts/"Kakumander"). In March 2011, the Grand Bench (daihōtei) of the Supreme Court ruled that the maximum discrepancy of 2.30 in voting weight between the Kōchi 3 and Chiba 4 constituencies in the 2009 election was in violation of the constitutionally guaranteed equality of all voters. As in previous such rulings on unconstitutional elections (1972, 1980, 1983 and 1990 Representatives elections, 1992 Councillors election), the election is not invalidated, but the imbalance has to be corrected by the Diet through redistricting and/or reapportionment of seats between prefectures.

The malapportionment in the 2010 regular House of Councillors election was ruled unconstitutional by the Supreme Court in October 2012.

The following table lists the 10 electoral districts with the highest and lowest number of registered voters per member elected for each chamber of the National Diet according to the voter statistics released by the Ministry of Internal Affairs and Communications in September 2011.