Japan is unused to changes in government. The country is a robust constitutional democracy, but it lacks a keen culture of competition among its political parties. Only once in the past halfcentury has the Liberal Democratic Party (LDP) lost office.

The LDP now faces the serious prospect of defeat, however. Taro Aso, the Prime Minister, has dissolved parliament and called an election for next month. He and his party deserve to lose. They exemplify a political system that has dissipated accountability and entrenched economic stagnation.

Mr Aso took office less than a year ago. The hope was that he would reassert the authority of the LDP despite the recession. He did more than fail in that endeavour: his personal poll ratings collapsed. His capacity for speaking his mind before formulating the thought within it has been exposed cruelly in contradictory policy statements. Economic failure is a pressing issue in the election. The opposition Democratic Party of Japan maintains that a huge programme of public spending is wasteful and represents an attempt to secure the support of sectional interests. That is a difficult criticism to argue with and is a potent reason for a change of government.

Economic stasis under the LDP is far from a recent development either. With the exception of a brief period of coalition government among the opposition parties in 1993-94, the LDP presided over the entire decade-long slump of the 1990s. Japan was once the most dynamic economy in the democratic world. Its rapid growth after 1945 was due not, as some admirers in Europe and the US believed, to industrial planning but to a huge shift from inefficient agriculture to manufacturing and services.

But then, in an augury of the financial disruption that swept the global economy in 2007-08, Japan suffered the aftershock of a massive bubble in asset prices. Bad debts overwhelmed banks that had lent huge sums in the property market. Prices fell consistently, discouraging consumer spending. Massive public spending was largely wasted on unproductive investment. The economy became burdened by excess capacity. Japan has never truly escaped this stasis.

The Western model of market capitalism has come under sustained criticism recently. But it has a benefit that Japan lacks: a capacity for industrial restructuring to improve economic performance. Japan’s political culture, with the dominance of a single party and an emphasis on compromise, militates against tough economic choices. Greater competition among parties might encourage fresh thinking.

Japan’s public debt has expanded dramatically to finance spending on infrastructure. Yet fiscal pressures will only increase. An ageing population will impose additional demands on health care and pension provision. Domestic reforms are urgent but will be difficult to accomplish in a recession. A change of government is not a sufficient condition of progress but it is probably a necessary one. A government with a mandate for change would also be helpful to Japan’s allies. With its wide external surplus, Japan ought to be well placed to help to stabilise the global economy. The election will be important on many grounds. But above all, it should demonstrate that democracy works best with a credible opposition.