Although the interest rate is 0% to 0.1%, 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%.

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Therefore, subtracting rising rates of inflation from falling nominal interest rates results in a falling real rate of interest.

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As a result, the real rate of interest nominal rates adjusted for inflation would actually rise in France.

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My good friend and sometime mentor, Brian Wesbury, argues that the natural rate of interest is the same as the nominal GDP growth rate.

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You need to read the speech for the full explanation, but the basic idea is that higher inflation can help push down the real cost of borrowing - the real interest rate - at times when nominal interest rates can't go any lower.

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Now to be clear I think the primary driver of low interest rates across the board is the presumption of weak nominal growth and that weak growth leading the Federal Reserve to keep a low interest rate target.

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