The extent of the 1990s bad loan problems of Japanese banks has received extensive press coverage. By the end of 1995, it was reasonably well-agreed that these problem loans amounted to some 100 trillion yen, or roughly 15% of outstanding loans. However, there is still little systematic analysis of the causes of the loan problem.
That is the task of this paper. We present evidence that, in the late 1980s and early 1990s, the approaching 1992 BIS capital standards, based as they are on accounting measures, had the perverse effect of giving banks an incentive to increase the risk of their loan portfolios; that the loan loss and bad debt write-off procedures helped banks pursue that incentive; that the incentive was compounded by the decline in profitability of banks' traditional business; and that the incentives could be acted upon, given the degree of deregulation in bank lending, i.e. relaxation of "window guidance," in the early 1980s.