These are tough times for banks. As the Bank of Japan's prolonged ultra-easy money policy weighs on earnings, the emergence of technology like artificial intelligence is transforming the mechanics of financing and threatening to replace thousands of roles with automated systems. The nation's major banks have announced restructuring measures including downsizing to deal with the situation and are rushing to catch-up with digital innovations, but some critics say it could be too late in the game. Negative interest rates introduced by the Bank of Japan in 2016 have been sapping the earning power of banks' core operations. The combined net core business profits of Japan's five big banks -- Mitsubishi UFJ Financial Group Inc. (MUFG), Sumitomo Mitsui Financial Group Inc. (SMFG), Mizuho Financial Group Inc., Resona Holdings Inc. and Sumitomo Mitsui Trust Holdings Inc. -- fell 22.4 percent in April-December from a year earlier, to ¥1.571 trillion.