Since the late 1980s, the coca-producing countries of South America, backed by money and expertise from the United States, have focused their counternarcotic efforts on finding and destroying illegal coca farms. The idea is a simple economic one: if you reduce the supply of a product, you increase its scarcity, driving up its price. Scarcity is what makes gold more expensive than silver, and oil more expensive than water: if lots of people want something, and there isn’t enough to go around, they have to pay more to get their hands on it.
