In a bold attempt to reflate the Japanese economy, the Bank of Japan has now pushed interest rates on deposits into negative territory. Though this policy is not new — it is already being pursued by the European Central Bank, the Bank of Sweden, the Swiss National Bank, and others — it is uncharted ground for the BOJ. And, unfortunately, markets have not responded as expected.

In theory, negative rates, by forcing commercial banks essentially to pay the central bank to be able to park their money, should spur increased lending to companies, which would then spend more, including on hiring more employees. This should spur a stock-market rebound, boost household consumption, weaken the yen's exchange rate, and halt deflation. But theory does not always translate into practice; while the BOJ's introduction of negative rates almost immediately pushed the interest-rate structure lower, as expected, the policy's effects on the yen and the stock market have been an unpleasant surprise.

One reason for this is widespread pessimism about Japan's economy, reinforced by volatility in China, monetary tightening in the United States, and the collapse in world oil prices. But, as BOJ Gov. Haruhiko Kuroda recently reported to the Upper House, Japan's economic fundamentals are generally sound, and pessimistic predictions are greatly exaggerated.