The Bank of Japan has begun shifting its focus from supporting growth to ways of phasing out its massive stimulus, taking first tentative steps towards a potentially momentous move for the world economy.
Current and former central bankers familiar with internal discussions say an informal debate is under way on how to prepare for an exit from the BOJ's 13-month-old "quantitative and qualitative monetary easing."
The stimulus is a centerpiece of Prime Minister Shinzo Abe's campaign to end two decades of deflation and fitful growth, and BOJ Governor Haruhiko Kuroda has vowed to keep cheap cash flowing until his 2 percent inflation target is in plain sight.
But with inflation now past the half-way mark and signs that the economy has weathered last month's sales tax increase, Japanese central bankers are already thinking about the next chapter.
First of all, Kuroda and his team are keen to avoid market confusion and volatility that the U.S. Federal Reserve triggered in May 2013 when it first signaled the possible "tapering" of its extraordinary stimulus.
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With the BOJ churning out 60-70 trillion yen per year ($589-687 billion), withdrawal symptoms could be similarly acute and the lesson for the BOJ is that signaling a tapering too soon or being too specific could backfire.
With that in mind, the BOJ has no plans to trim the stimulus or publicly suggest the eventual drawdown any time soon, say those familiar with the internal debate.
But whereas weeks or months ago that debate would center on the potential need for more easing, now there is a strong sense within the BOJ board that the stimulus so far has worked well and the next step, albeit distant, could be policy tightening, not further easing.
Deputy Governor Kikuo Iwata underscored that shift, reminding markets that the 2 percent inflation goal worked both ways.
"The BOJ's current policy intends to prevent not just deflation but inflation from well exceeding 2 percent, such as to 4 percent or 5 percent, for a medium- to long-term period," Iwata told a seminar on Monday.
Hideo Hayakawa, a former top BOJ economist who maintains close contacts with those inside, says the central bank needs to clarify what will it do after the battle with deflation is won.
"If 2 percent inflation comes into sight, the BOJ should taper its asset purchases," Hayakawa, a senior executive fellow at private think-tank Fujitsu Research Institute, told a Reuters Investment Summit last week.
In public, Kuroda has become more vocal about the need for government structural reforms, which shows he wants the BOJ to shift from boosting economic demand to playing a supporting role as Abe promises deregulation to boost Japan's growth potential.