Negative interest rates are a mistake in Japan. Today's announcement could prove critical in the currency war. China's announcement that they will target a basket of currencies is for real this time and the yen is roughly 15% of that basket. The euro is a further 21% and BoJ aggression will heap pressure on the ECB to act in March. With all the other major central banks looking to devalue, the risk of ever greater USD strength means it will now be difficult for the Fed to send a strong message on the health of the economy by hiking rates in March. (LSR Daily Note 29th January 2016)
ECB cut rates and expanded QE programme on 10th March, Fed did not hike.