The Japanese economy is not just being propped up by the bank of Japan its more than that. The bank of Japan essentially IS the economy at this point it owns over 75% of the Nikkei 225 and owns close to a majority of JGB's. Central banks across the globe follow the bank of Japan because it is the furthest in the hole exceeding all its peers by a massive margin. The ECB is less than halfway to where Japan is, at around 65% of assets to GDP, the bank of Japan is at over 135%. This is the only bank in the world that can cause a truly massive shock and catch the world off guard because people just ASSUME they will stay the course forever at this point. However something has to give eventually the BOJ will pretty much own the nations entire economy sometime before 2050 at this rate. Which would leave Japan as this bizarre pseudo capitalist nation where you have financial markets and companies but the government pretty much owns everything. Pay close attention to the bank of Japan because this is the largest and one of the most dangerous financial experiments in history.