After increasing the amount of its asset purchases further in 2014, it adopted a negative interest rate policy in January 2016 and introduced QQE with Yield Curve Control in September of that year.
Since the introduction of QQE, the basic mechanism of monetary easing itself has not changed; that is, (1) pushing down the entire yield curve through the Bank's large-scale purchases of Japanese government bonds (JGBs), and (2) raising inflation expectations through the Bank's strong commitment to the 2 percent price stability target.