"the interest rate is 0% to 0.1%(in Japan), average deflation of -1.3% in the past 15 years means that the real interest rate (nominal interest rate 0% minus the price change of -1.3%) is a positive 1.3%."
Source:Abenomics: Can it really end deflation in Japan?
By Linda Yueh
BBC News
25 April 2013