The July 2016 House of Councillors election, in which a ballot cast in the least populated constituency carried 3.08 times the weight of one cast in the most crowded constituency, was consistent with the Constitution, the Supreme Court has ruled. In other words, the court decided that it could not call the vote value disparity egregiously unfair.
In 2012 and 2014, the court categorized the 2010 and 2013 upper house elections as "in a state of unconstitutionality," with vote value disparities of 5.00 and 4.77, respectively. It also urged the Diet to drastically reform the demarcation system, under which each prefecture had one constituency, to correct the problem.
In response, last year the Diet passed revisions to the Public Offices Election Act to merge the upper house Tottori and Shimane prefectural constituencies, and Tokushima and Kochi constituencies, and eliminate 10 seats in sparsely populated regions, while adding 10 in high-population areas.
The Supreme Court's most recent decision was in effect an affirmation of the Diet's actions to shrink the vote value imbalance from its longtime high of around 5.00. However, the court also credited a supplementary provision in the election law revision in 2015 -- specifically, a promise that the Diet would consider and implement drastic changes to the Japanese electoral system ahead of the next election -- for helping it conclude that the vote was in line with the Constitution.
The provision "demonstrated the legislature's determination to move to further correct the (vote value) disparity," the ruling stated. That is, the court included expectations for future action in its decision, and it most certainly did not grant its imprimatur for the current state of affairs. The Diet must not cease its efforts to reduce vote value disparity, but rather redouble them.
While the court ruling praised the reduction in this disparity, voter turnout in all the prefectures that had their constituencies merged (save Shimane) plummeted to record lows in the last election. It would be a serious problem indeed if the giant, two-prefecture districts make elections feel distant to many constituents, inviting voter apathy.
As Japan's population increasingly concentrates in its big cities, correcting the vote value disparity will entail yet more constituency mergers. We need to be mindful of this trend's adverse effects as well.
There is little common ground among the political parties on electoral reform. However, the court ruling calls for vote value fairness in upper house elections -- a sharp prod at the parties to get reform rolling. If political parties remain at odds over electoral reform, the disparity will only widen again, and likely prompt a sharp rebuke in the courts.
If reform talks are limited to changing electoral district boundaries, it will be difficult indeed to solve the vote value problem.
In Japan's bicameral system, how should the roles of the chambers be divided? Furthermore, what is the upper house's raison d'etre? Substantive, far-reaching discussion is needed if we are to reach a sweeping solution to this country's electoral woes.