Bank of Japan Governor Haruhiko Kuroda said at a seminar in Tokyo on March 7 that negative interest rates would have a "very powerful" stimulus effect on the economy by driving down borrowing costs and nudging firms into boosting investment.

However, things are not faring well.

Although Abenomics has produced some results, including record corporate earnings and the highest levels of employment in a quarter of a century, Japan's companies are sitting on more than 340 trillion yen ($2.9 trillion), and they have shied away from raising wages or making sizable investments in Japan. Instead, they are buying back their own shares. Thomson Reuters data show that companies took advantage of the low prices to buy back a total $9.3 billion in shares in February alone, the highest since Nov 2010.