Several African countries with rich endowments of mineral resources and petroleum have, paradoxically, achieved less by way of economic development than other African states without such wealth. In the African mineral economies there is less diversification of production, less investment, higher foreign debt, greater unemployment, and weaker overall productive growth. The causes of this poor economic performance involve both external factors, such as declining prices of primary commodity products, and internal factors, such as rent-seeking activities of politically powerful groups which give their support to governmental leaders in return for access to wealth. Inevitably, the mineral industries, which depend on timely investments and good management, decline. As a result the governments then resort to heavy foreign borrowing.