Purchasing power,interest rate parities and the modified Fisher effect in presence of tax agreements

This paper shows that in a world with different rates of inflation and taxation, in the presence of an international tax agreement, the simultaneous coexistence of the purchasing power parity mechanism, the interest rate parity mechanism, and the revised Fisher effect is impossible. The analysis reveals a possible inherent instability of interest rates and exchange rates generated by inflation. This instability is greater the larger the tax rate differentials among countries.