A cartel is a counterfeit agreement among industries. It is an informal organization of producers that agree to coordinate prices and production.

Several economic studies and legal decisions of antitrust authorities have found that the median price increase achieved by cartels in the last 200 years is around 25%. Private international cartels (those with participants from two or more nations) had an average price increase of 28%, whereas domestic cartels averaged 18%. Less than 10% of all cartels in the sample failed to raise market prices.

Private vs public cartel

A distinction needs to be drawn between public and private cartels. In the case of public cartels, the government may establish and enforce the rules relating to prices, output and other such matters. Export cartels and shipping conferences are examples of public cartels. In many countries, depression cartels have been permitted in industries deemed to be requiring price and production stability and/or to permit rationalization of industry structure and excess capacity. In Japan for example, such arrangements have been permitted in the steel, aluminum smelting, ship building and various chemical industries. Public cartels were also permitted in the United States during the Great Depression in the 1930s and continued to exist for some time after World War II in industries such as coal mining and oil production. Cartels have also played an extensive role in the German economy during the inter-war period. International commodity agreements covering products such as coffee, sugar, tin and more recently oil (OPEC) are examples of international cartels which have publicly entailed agreements between different national governments. Crisis cartels have also been organized by governments for various industries or products in different countries in order to fix prices and ration production and distribution in periods of acute shortages.

In contrast, private cartels entail an agreement on terms and conditions from which the members derive mutual advantage but which are not known or likely to be detected by outside parties. Private cartels in most jurisdictions are viewed as being illegal and in violation of antitrust laws.

Long-term unsustainability of cartels

Some argue that cartels are inherently unstable via game theory arguments, particularly the prisoner's dilemma. By staying silent (cooperating) both prisoners are better off than in the case where both decide to betray (deviate from the agreement, that is, competing). Nevertheless, if only one of the two prisoners betray while the other stays silent, the former would be free, which is still more desirable for him than having to stay in prison for six months.

The same may occur in a cartel if the market is inherently limited (as opposed to the market remaining in existence indefinitely: while their members are better-off being part to the agreement than competing, deviating (for example by reducing one's price) could imply capturing a big amount of the market demand and making big profits. In other words, the members of a cartel always have an incentive to deviate from their agreement which explains why cartels are generally difficult to sustain in the long run. Empirical studies of 20th century cartels have determined that the mean duration of discovered cartels is from 5 to 8 years. However, once a cartel is broken, the incentives to form the cartel return and the cartel may be re-formed.