Assume that Canadian wheat sells for $100 per bushel, Russian wheat sells for 1,600 rubles per bushel, and the nominal exchange rate is 4 rubles per dollar. What is Purchasing Power Parity (PPP) and does it hold between Russian and Canadian wheat? According to PPP, what would happen to the real exchange rate between Canadian Russian wheat in the long run, and why? For which types of goods is PPP least likely to be applicable?