The Relationship between Nominal Interest Rates and Inflation: New Evidence and Implications for Nigeria

Abstract

This paper investigates the relationship between expected inflation and nominal interest rates in Nigeria and the extent to which the Fisher effect hypothesis holds, for the period 1970-2009. The real interest rate is obtained by subtracting the expected inflation rate from the nominal interest rate. For the Fisher hypothesis to hold, the resultant ex ante real interest rate should be stationary. Using the Johansen Cointegration Approach and Error Correction Mechanism, our findings tend to suggest: (i) the real interest rates is stationary (ii) that the nominal interest rates and expected inflation move together in the long run but not on one-to-one basis. This indicates that full Fisher hypothesis does not hold but there is a very strong Fisher effect in the case of Nigeria over the period under study (iii) that causality run strictly from expected inflation to nominal interest rates as suggested by the Fisher hypothesis and there is no “reverse causation” (iv) that only about 16 percent of the disequilibrium between long term and short term interest rate is corrected within the year. Policy implication, based on the partial Fisher effect in Nigeria, is that the level of actual inflation should become the central target variable of the monetary policy.

Keywords: Fisher Effect, Co-integration, Error Correction Model, Nigeria