Back in the 1980s, when I was serving as a Peace Corps Volunteer in Ghana, I lived in the Northern Region in a small town called Tamale. The economic situation in the country was bad. The currency, the cedi, had a fixed official exchange rate of three cedi to one U.S. dollar. That rate wasn’t realistic. Goods were priced according to the black market rate, which was closer to one hundred cedi to a dollar.