This study investigates the validity of both the conventional and tax-adjusted Fisher effects using time series methods such as the ARDL bounds test, and Gregory-Hansen (G-H) cointegration test. To compare the conventional and tax-adjusted Fisher effects, we use two different time series data for interest rates: 1) interest rates adjusted for taxes, and 2) interest rates not adjusted for taxes. Using monthly changes in quarterly and annual interest and inflation rates, both the G-H and ARDL bound tests support the conventional and tax-adjusted Fisher effects. However, the magnitude of the inflation coefficient in the long-run relationship tends to decline for the tax adjusted Fisher effect
