Fisher equations inverted and not

Regressions of the realized real after-tax interest rate on theex post rate of inflation are shown to be incapable of discriminating between the competing hypotheses that the real after-tax interest rate is not effected by expected inflation due to the substitutability between debt and equity (the Fisher hypothesis); and, that the nominal after-tax interest rate is not effected by expected inflation due to the substitutability between money and debt (the inverted Fisher hypothesis). An alternative regression which is so capable, is shown to reject the inverted and support the original Fisher hypothesis.