DID Japanese main banks improve the technical efficiencies of their non-financial client firms in the 1980s?

This paper tests the hypothesis that the Japanese main bank system was not effective in enhancing technical efficiency in the non-financial corporate sector in the 1980s. Technical efficiency is defined as the ratio of a firm's actual to its potential output for given input levels and technology. During the eighties, it did not improve consistently and significantly in Japanese manufacturing firms which have close ties to a main bank.