The study looked at how changes in the prices of goods traded internationally affect the economies of countries that export oil. They focused on 18 oil-exporting countries from 1973 to 1989. The researchers found that when the prices of oil go up permanently, these countries tend to invest more in things like machinery. This leads to an increase in government spending, but not in savings. The countries also end up importing more than they export, which affects their trade balance. Surprisingly, the oil industry doesn't take over other sectors like agriculture or manufacturing, possibly because of government policies or the way the oil industry operates separately from the rest of the economy.