Pii: S0921-8009(98)00085-8

As economic systems develop over time they tend to become more complex with more structure and greater throughputs, assuming favorable conditions. Energy use increases as more economic sectors develop and more channels for flow are opened. Economic diversity, as measured by the number of economic sectors using energy and the equatability of flows between them, generally increases. As diversity increases the efficiency of generating outputs with a given amount of energy also increases. Development capacity, the product of system energy throughput and diversity of flows, is a measure of the potential system output and is calculated for selected countries. Capacity changes over time are shown to relate to changes in economic output in selected countries. Two distinct development strategies become evident, one which promotes energy use and one which emphasizes diversity. While most countries utilize a mix of the two, developing countries generally rely more on increasing energy use to increase output while developed countries tend to become more diverse as a means of increasing outputs. Sustainability is enhanced by strategies which promote diversity and resource use efficiency in economic systems. © 1999 Elsevier Science B.V. All rights reserved.