需要と供給
Supply and demand are generally accepted as market functions for establishing prices. Organisations typically endeavor to 1) minimize the cost of production; 2) increase sales; in order to 3) maximize profits. But, according to David Schweickart, if "those who produce the goods and services of society are paid less than their productive contribution", then as consumers they cannot buy all the goods produced, and investor confidence tends to decline, triggering declines in production and employment. Such economic instability stems from a central contradiction: Wages are both a cost of production and an essential source of effective demand (needs or desires backed with purchasing power), resulting in deficiency of effective demand along with a growing interest in economic democracy.