Look at that, the Bank of Japan has joined other central banks in announcing an explicit inflation target, and doing all they can to show their credibility for achieving it.
Some will call this a currency war, or “monetization” – but again, this is the Bank targeting a specific inflation target in a forward looking manner. This is what they should have been doing all along – and given it is a rule, it helps set expectations and acts as a “no-monetization” condition.
Some will say this destroys central bank independence. I would note that the purpose of independence is to sovle “time inconsistency” in central banks – rule based policy does this fine. It would only be a problem if the Japanese government tried to force them to violate the rule.
New Zealander’s will complain about the dollar. Remember here that the BOJ has commited to inflation of 2%pa (where previously it was expected to, on average, be lower). The return on holding a Yen has become more negative per year … and so the asset price of the Yen much fall. This is what has happened, however the price inflation will ensure that the real exchange rate trends back to its true level. Remember, the exchange rate is a price, and we need to think about the primitive causes of any issue in order to figure out if there is one. The BOJ actually doing normal monetary policy isn’t negative for NZ – although it will sting the bottom line of people trying to sell to Japan in the near term (hola Rio Tinto).