Sony Financial Group economist Tetsuya Inoue said the Bank of Japan's decision to cite upside inflation risk as the rationale for a rate increase marks a clear shift in policy logic. Previously the BOJ framed tightening as a means to achieve the 2% inflation target in a stable, sustainable manner. Inoue warned that if the BOJ lags developments, long-term government bond yields could spike, the yen could weaken further, and inflation could accelerate.