Richard Posner is unsurprised that Japan likely "failed to take cost-justified measures to minimize the damage from a 9.0 or greater earthquake":
Politicians have limited time horizons. If the annual probability of some catastrophe is 1 percent, and a politician’s horizon is 5 years, he will be reluctant to support significant expenditures to reduce the likelihood or magnitude of the catastrophe, because to do so would involve supporting either higher taxes or a reallocation of government expenditures from services that provide immediate benefits to constituents.
In principle, it is true, politicians would take a long view if their constituents did out of concern for their children and grandchildren. But considering how the elderly cling to their social benefits, paid for by the young including their own young, I doubt the strength of that factor, although I do not know enough about Japanese politics to venture a guess on whether politicians’ truncated policy horizons was indeed a factor in Japan’s surprising lack of preparations for responding promptly and effectively to the kind of disaster that has occurred.