Japan's top-rated economist says the central bank doesn't need more stimulus, defying the consensus.

Ryutaro Kono, chief Japan economist in Tokyo at BNP Paribas SA and who was voted No. 1 by Nikkei Veritas magazine in six of the past seven years, says lower oil prices will stimulate growth and policymakers will favor yen stability.

Twenty-six of 33 of economists surveyed by Bloomberg forecast that the Bank of Japan will accelerate asset purchases by the end of October to meet its 2 percent inflation target. Ten-year inflation swaps slid to a two-year low of 0.74 percent this week, Meitan Tradition data showed.