A key economic objection to unregulated, profit-maximizing monopoly is that in the short run monopolists: do not try to minimize the costs of the level of output they produce. produce a level of output at which marginal revenue is greater than marginal cost. produce too many products, which they sell at prices that are too high, earning economic profits. restrict output to levels at which their products are valued more than the marginal cost of producing them.

The business cycle is the periodic but irregular up-and-down movement in economic activity, measured by fluctuations in real gross domestic product (gdp) and other macroeconomic variables. a business cycle is typically characterized by four phases—recession, recovery, growth, and decline—that repeat themselves over time. economists note, however, that complete business cycles vary in length. the duration of business cycles can be anywhere from about two to twelve years, with most cycles averaging six years in length. some business analysts use the business cycle model and terminology to study and explain fluctuations in business inventory and other individual elements of corporate operations. but the term "business cycle" is still primarily associated with larger (industry-wide, regional, national, or even international) business trends.