Concentration of exports on a narrow range of categories of goods and services, or a narrow range of countries. The higher its degree of export concentration, the more liable are a country's balance of trade and national income to disruption by fluctuations in the sectors of the world economy in which it is concentrated. More widely dispersed markets give a lower degree of risk. Export concentration is generally highest in some of the oil-exporting countries, and some of the world's smaller primary commodity exporters. It is generally low in industrial countries.