The availability of micro-, mini-, and supercomputers has complicated the laws governing the economies of scale in computers. A recent study by Ein-Dor  concludes that it is most effective to accomplish any task on the least powerful type of computer capable of performing it. This change in cost/performance, and the promise of increased reliability, modularity, and better response time has resulted in an increased tendency to decentralize and distribute computing power. But some economic factors, such as the communication expenses incurred and increased storage with distributed systems are working against the tendency to decentralize. It is clear that in many instances the optimal solution will be an integration of computers of varying power.