Why Seiji Adachi Says the BOJ Is “Pretty Much Boxed In”

Former Bank of Japan board member Seiji Adachi expects the central bank to raise its policy rate to 1.25% at the September 18 meeting, followed by a possible additional increase as early as January. Traders were pricing roughly an 80% probability of a September hike on August 24–25. 345

That market positioning is central to Adachi’s argument: the BOJ may now face greater risks from holding rates steady than from delivering the increase investors expect.

Adachi’s expected BOJ path

Adachi’s near-term forecast is for a September hike that would take the policy rate from 1.0% to 1.25%, with another move possible in January. The forecast is consistent with his earlier view that the BOJ could move to 1.25% between October and January and potentially reach 1.5% to 1.75% the following year. 19

This would represent a continuation of monetary-policy normalization, but the timing matters. A September move would validate expectations that rose sharply after the yen’s post-intervention gains began to fade. A delay could force markets to reassess the BOJ’s willingness to respond to currency weakness and inflation pressure.

Why Adachi says the BOJ is “boxed in”

Adachi’s “boxed in” assessment reflects a market-expectations problem. With traders already assigning around an 80% chance to a September hike, a decision to hold could be interpreted as a dovish surprise rather than a neutral pause. 34

In his view, that surprise could trigger renewed yen selling. The yen had weakened toward ¥159 per dollar even after a joint U.S.-Japan effort to counter speculative pressure, leaving the currency close to the psychologically important ¥160 level. 3171827

The issue is therefore not that the BOJ has lost all policy choice. Rather, the central bank’s communications and previous policy signals have made a hold potentially more disruptive for markets than a carefully explained increase.

The yen intervention raised the pressure

The late-July currency intervention temporarily supported the yen, but the effect was not viewed as a complete solution. Reuters reported that markets increased the implied probability of a September BOJ hike from 24% on July 30 to 76% by August 13. 17

That shift followed calls from U.S. Treasury Secretary Scott Bessent for Japan to support intervention with appropriate “policy and fundamentals.” The comments were interpreted as pressure for a monetary-policy stance that would better support the yen. 17

Reports also said Prime Minister Sanae Takaichi’s government supported a near-term BOJ move, with September or October identified as the likely window. 22 At the same time, reporting described a policy tension between pressure to support the currency through higher rates and concern that aggressive tightening could damage growth. 1823

A faster pace remains the main market question

The September decision would provide an immediate test of the BOJ’s reaction function, but investors are also watching for clues about the pace of future hikes. A sequence of moves in September and January would be more rapid than a strictly cautious normalization path.

That is why speeches by BOJ officials have become important. Deputy Governor Ryozo Himino was scheduled to speak on August 27, while other board members were also due to address markets before the September meeting. Their comments could indicate whether the central bank is preparing investors for another gradual adjustment or a more active hiking cycle. 26

Adachi’s current position is more forceful than his earlier public warnings that rate increases should proceed at a “very moderate” pace and avoid prematurely weakening Japan’s recovery. 13 The change does not necessarily mean he views tightening as risk-free; it suggests that currency weakness and persistent price pressure now weigh more heavily in his assessment of the balance of risks.

What could challenge the forecast?

Adachi’s view remains a forecast, not a commitment by the BOJ. The central bank could still delay a hike if officials judge that domestic demand, wages or the broader recovery are too fragile. Earlier BOJ commentary also emphasized the danger of raising rates too soon if doing so undermined the recovery. 213

The most reliable near-term signals will therefore be the BOJ’s own communication, incoming inflation and growth data, and the yen’s response to any change in expectations. A September hike may be the market base case, but the size and pace of subsequent moves will depend on whether inflation proves durable without causing a sharper slowdown.

Bottom line

Adachi’s message is that the BOJ is more likely to meet the market’s September 18 expectations than to disappoint them. He sees another hike in January as possible and warns that standing still could weaken the yen again, undermining the effect of intervention and adding to import-driven inflation concerns. 456

The bigger question is whether the September move marks a continued gradual normalization or the start of a faster sequence. Himino’s speech and other BOJ communications ahead of the meeting are expected to offer the clearest clues. 26