Information economics

Information economics

Information economics or the economics of information is a branch of microeconomic theory that studies how information affects an economy and economic decisions. Information has special characteristics. It is easy to create but hard to trust. It is easy to spread but hard to control. It influences many decisions. These special characteristics (as compared with other types of goods) complicate many standard economic theories.

The subject is treated under "Journal of Economic Literature" classification code . The present article reflects topics included in that code. There are several subfields of information economics. The first insights in information economics related to the economics of information goods. In recent decades, there have been influential advances in the study of information asymmetries and their implications for contract theory. Finally, with the rise of computers, economists have begun to study economics of information technology.

Value of information

The starting point for economic analysis is the observation that information has economic value because it allows individuals to make choices that yield higher expected payoffs or expected utility than they would obtain from choices made in the absence of information.

Information asymmetry

Information asymmetry deals with the study of decisions in transactions where one party has more or better information than the other. This creates an imbalance in power in transactions which can sometimes cause the transactions to go awry. Examples of this problem are Adverse selection and Moral hazard.

A classic paper on adverse selection is George Akerlof's The Market for Lemons. There are two primary solutions to this problem, signalling and screening.


Michael Spence originally proposed the idea of signaling. He proposed that in a situation with information asymmetry, it is possible for people to signal their type, thus believably transferring information to the other party and resolving the asymmetry.

This idea was originally studied in the context of looking for a job. An employer is interested in hiring a new employee who is skilled in learning. Of course, all prospective employees will claim to be skilled at learning, but only they know if they really are. This is an information asymmetry.

Spence proposed that going to college can function as a credible signal of an ability to learn. Assuming that people who are skilled in learning can finish college more easily than people who are unskilled, then by attending college the skilled people signal their skill to prospective employers. This is true even if they didn't learn anything in school, and school was there solely as a signal. This works because the action they took (going to school) was easier for people who possessed the skill that they were trying to signal (a capacity for learning).


Joseph E. Stiglitz pioneered the theory of screening. In this way the underinformed party can induce the other party to reveal their information. They can provide a menu of choices in such a way that the choice depends on the private information of the other party.

Information goods

Buying and selling information is not the same as buying and selling most other goods. First of all, information is non-rivalrous, which means that consuming information does not exclude someone else from also consuming it. A related characteristic that alters information markets is that information has almost zero marginal cost. This means that once the first copy exists, it cost nothing or almost nothing to make a second copy. This makes it easy to sell over and over. However, it makes classic marginal cost pricing completely infeasible.

Second, exclusion is not a natural property of information goods, though it is possible to construct exclusion artificially. However, the nature of information is that if it is known, it is difficult to exclude others from its use. Since information is likely to be both non-rivalrous and non-excludable, it is frequently considered an example of a public good.

Third is that the information market does not exhibit high degrees of transparency. That is, to evaluate the information the information must be known, so you have to invest in learning it to evaluate it. To evaluate a bit of software you have to learn to use it; to evaluate a movie you have to watch it.

The importance of these properties is explained by Froomkin, in [ The Next Economy] .


One method of taking advantage of information goods is bundling. That is the strategy of grouping multiple items together and selling them as a group. Bundling allows sellers to better predict the demand for the bundle. While it is difficult to know which items in the group an individual person wants, they are likely to value some of the items enough to purchase the bundle, even if they don't value any of the items enough to buy it separately. However, this only works when it doesn't cost much to sell extra items in a bundle that are unwanted. Information goods fit this profile since it doesn't cost anything to make extra copies.

More Information

In 2001, the Nobel prize in economics was awarded to George Akerlof, Michael Spence, and Joseph E. Stiglitz "for their analyses of markets with asymmetric information." []

ee also

*Contract theory
*Adverse selection
*Moral hazard
*Bundling (marketing)


*Akerlof, G. (1970). The market for lemons: quality uncertainty and the market mechanism. "Quarterly Journal of Economics" 84 (3), 488-500.
*Birchler, U.W., and M. Bütler (2007). "Information Economics". London, Routledge. ISBN 978-0415373463 []
* Lippman, S. S., and J. J. McCall (2001). "Information, Economics of," "International Encyclopedia of the Social & Behavioral Sciences", pp. 7480-7486. [,151000134&_fmt=summary&_orig=na&_docanchor=&_idxType=SC&view=c&_ct=28&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=748a6fddc8a0c1b70f58f6d282af81fd Abstract.]
*Maasoumi, Esfandiar (1987). "Information theory," "", v. 2, pp. 846-51.
*Mas-Colell, Andreu; Michael D. Whinston, and Jerry R. Green (1995), "Microeconomic Theory". Oxford University Press. Chapters 13 and 14 discuss applications of adverse selection and moral hazard models to contract theory.
*Shapiro, Cark, and Hal R. Varian (1999). "Information Rules: A Strategic Guide to the Network Economy". Harvard University Press. (publisher's [ excerpts] )
*Spence, A.M.: "Job Market Signaling", "Quarterly Journal of Economics" 83 (1973), pp. 355-377.
*Stigler, George J. (1961). “The Economics of Information,” "Journal of Political Economy", June. [ (JSTOR))]
* Stiglitz, Joseph E. (2000). "The Contributions of the Economics of Information to Twentieth Century Economics," "Quarterly Journal of Economics", 115(4) , pp. 1441-1478. []
*Theil, Henri (1967). "Econonomics and Information Theory". Amsterdam, North Holland.

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