The document discusses interest rate parity (IRP) and purchasing power parity (PPP). IRP states that interest rate differences between countries equal the forward exchange rate minus the spot rate. PPP holds that currency exchange rates adjust so goods cost the same across countries when prices are converted to the same currency. Violations of IRP create arbitrage opportunities. Factors like inflation rates, economic conditions, and monetary policies influence IRP and PPP over time. Formulas are provided for calculating IRP and expected future exchange rates under PPP.