Economists from Nomura Holdings Inc. to BNP Paribas SA lowered their forecasts for the economy this week, making the central bank's growth outlook for this year look increasingly optimistic.

The trigger — a second-quarter contraction reported on Monday — also led Bank of America Corp. and NLI Research Institute to trim their projections for the fiscal year through March 2016. The world's third-biggest economy is now set to grow 1.2 percent over the 12 months, according to the median of 13 estimates from economists, less than the 1.7 percent forecast by the Bank of Japan.

The upshot is likely to be the BOJ reducing its growth outlook when it provides updated projections on Oct. 30, fanning speculation for another boost in monetary stimulus. Slower growth would add to headwinds for the central bank, as declines in the price of oil and other commodities dim prospects for the pickup in inflation.