![Concorde 216 (G-BOAF) last flight](https://upload.wikimedia.org/wikipedia/commons/3/39/Concorde_216_%28G-BOAF%29_last_flight.jpg)
In
economics
Economics () is the social science that studies the Production (economics), production, distribution (economics), distribution, and Consumption (economics), consumption of goods and services.
Economics focuses on the behaviour and intera ...
and business
decision-making
In psychology, decision-making (also spelled decision making and decisionmaking) is regarded as the Cognition, cognitive process resulting in the selection of a belief or a course of action among several possible alternative options. It could be ...
, a sunk cost (also known as retrospective cost) is a
cost
In production, research, retail, and accounting, a cost is the value of money that has been used up to produce something or deliver a service, and hence is not available for use anymore. In business, the cost may be one of acquisition, in which ...
that has already been incurred and cannot be recovered.
Sunk costs are contrasted with ''
prospective costs'', which are future costs that may be avoided if action is taken.
In other words, a sunk cost is a sum paid in the past that is no longer relevant to decisions about the future.
Even though economists argue that sunk costs are no longer relevant to future rational decision-making, people in everyday life often take previous expenditures in situations, such as repairing a car or house, into their future decisions regarding those properties.
Bygones principle
According to
classical economics
Classical economics, classical political economy, or Smithian economics is a school of thought in political economy that flourished, primarily in Britain, in the late 18th and early-to-mid 19th century. Its main thinkers are held to be Adam Smith ...
and standard
microeconomic
Microeconomics is a branch of mainstream economics that studies the behavior of individuals and firms in making decisions regarding the allocation of scarce resources and the interactions among these individuals and firms. Microeconomics fo ...
theory, only prospective (future) costs are relevant to a
rational
Rationality is the quality of being guided by or based on reasons. In this regard, a person acts rationally if they have a good reason for what they do or a belief is rational if it is based on strong evidence. This quality can apply to an abili ...
decision. At any moment in time, the best thing to do depends only on ''current'' alternatives.
The only things that matter are the ''future'' consequences.
Past mistakes are irrelevant.
Any costs incurred prior to making the decision have already been incurred no matter what decision is made. They may be described as "water under the bridge",
and making decisions on their basis may be described as "crying over spilt milk". In other words, people should not let sunk costs influence their decisions; sunk costs are irrelevant to rational decisions. Thus, if a new factory was originally projected to yield $100 million in value, and after $30 million is spent on it the value projection falls to $65 million, the company should abandon the project rather than spending an additional $70 million to complete it. Conversely, as a rational actor, if the value projection falls to $75 million the company should continue the project. This is known as the ''bygones principle''
or the ''marginal principle''.
The bygones principle is grounded in the branch of
normative
Normative generally means relating to an evaluative standard. Normativity is the phenomenon in human societies of designating some actions or outcomes as good, desirable, or permissible, and others as bad, undesirable, or impermissible. A norm in ...
decision theory
Decision theory (or the theory of choice; not to be confused with choice theory) is a branch of applied probability theory concerned with the theory of making decisions based on assigning probabilities to various factors and assigning numerical ...
known as ''
rational choice theory
Rational choice theory refers to a set of guidelines that help understand economic and social behaviour. The theory originated in the eighteenth century and can be traced back to political economist and philosopher, Adam Smith. The theory postula ...
'', particularly in
expected utility hypothesis The expected utility hypothesis is a popular concept in economics that serves as a reference guide for decisions when the payoff is uncertain. The theory recommends which option rational individuals should choose in a complex situation, based on the ...
. Expected utility theory relies on a property known as ''cancellation'', which says that it is rational in decision-making to disregard (cancel) any state of the world that yields the same outcome regardless of one's choice. Past decisions—including sunk costs—meet that criterion.
The bygones principle can also be formalised as the notion of “separability”. Separability requires agents to take decisions by comparing the available options in eventualities that can still occur, uninfluenced by how the current situation was reached or by eventualities that are precluded by that history. In the language of decision trees, it requires the agent’s choice at a particular choice node to be independent of unreachable parts of the tree. This formulation makes clear how central the principle is to standard economic theory by, for example, founding the folding-back algorithm for individual sequential decisions and game-theoretical concepts such as sub-game perfection.
Until a decision-maker irreversibly commits resources, the prospective cost is an
avoidable future cost and is properly included in any decision-making process.
For instance, if someone is considering pre-ordering movie tickets, but has not actually purchased them yet, the cost remains avoidable.
Both retrospective and prospective costs could be either
fixed cost
In accounting and economics, 'fixed costs', also known as indirect costs or overhead costs, are business expenses that are not dependent on the level of goods or services produced by the business. They tend to be recurring, such as interest or r ...
s (continuous for as long as the business is operating and unaffected by output volume) or
variable cost
Variable costs are costs that change as the quantity of the good or service that a business produces changes.Garrison, Noreen, Brewer. Ch 2 - Managerial Accounting and Costs Concepts, pp 48 Variable costs are the sum of marginal costs over all un ...
s (dependent on volume).
However, many economists consider it a mistake to classify sunk costs as "fixed" or "variable." For example, if a firm sinks $400 million on an enterprise software installation, that cost is "sunk" because it was a one-time expense and cannot be recovered once spent. A "fixed" cost would be monthly payments made as part of a service contract or licensing deal with the company that set up the software. The upfront irretrievable payment for the installation should ''not'' be deemed a "fixed" cost, with its cost spread out over time. Sunk costs should be kept separate. The "variable costs" for this project might include data centre power usage, for example.
There are cases in which taking sunk costs into account in decision-making, violating the bygones principle, is rational.
For example, for a manager who wishes to be perceived as persevering in the face of adversity, or to avoid blame for earlier mistakes, it may be rational to persist with a project for personal reasons even if it is not the benefit of their company. Or, if they hold private information about the undesirability of abandoning a project, it is fully rational to persist with a project that outsiders think displays the fallacy of sunk cost.
Fallacy effect
The bygones principle does not always accord with real-world behavior. Sunk costs do, in fact, often influence people's decisions,
with people believing that investments (i.e., sunk costs) justify further expenditures. People demonstrate "a greater tendency to continue an endeavor once an investment in money, effort, or time has been made."
This is the sunk cost fallacy, and such behavior may be described as "throwing good money after bad",
while refusing to succumb to what may be described as "cutting one's losses".
For example, some people remain in failing relationships because they “have already invested too much to leave.” Still others are swayed by arguments that a war must continue because lives will have been sacrificed in vain unless victory is achieved. Likewise, individuals caught up in psychic scams will continue investing time, money and emotional energy into the project, despite doubts or suspicions that something is not right.
These types of behaviour do not seem to accord with rational choice theory and are often classified as behavioural errors.
Rego, Arantes, and Magalhães point out that the sunk cost effect exists in committed relationships, and they devised two experiments that showed that people in a relationship that invested money and effort were more likely to keep the relationship rather than end it, and in a relationship that had invested enough time relationship, they tend to devote more time to the relationship. It also means that people fall into the sunk cost fallacy. Although people should ignore sunk costs and make rational decisions when making decisions about the future, time, money, and effort often make people continue to maintain this relationship, which is equivalent to continuing to invest in failed projects.
According to evidence reported by De Bondt and Makhija (1988), managers of many utility companies in the United States have been overly reluctant to terminate economically unviable nuclear plant projects. In the 1960s, the nuclear power industry promised “energy too cheap to meter.” But nuclear power later lost public support. In the 1970s and 1980s, public service commissions around the nation ordered prudency reviews. From these reviews, De Bondt and Makhija find evidence that the commissions denied many utility companies even partial recovery of nuclear construction costs on the grounds that they had been mismanaging the nuclear construction projects in ways consistent with throwing good money after bad.
There is also evidence of government representatives failing to ignore sunk costs.
The term "Concorde fallacy" derives from the fact that the British and French governments continued to fund the joint development of the costly
Concorde
The Aérospatiale/BAC Concorde () is a retired Franco-British supersonic airliner jointly developed and manufactured by Sud Aviation (later Aérospatiale) and the British Aircraft Corporation (BAC).
Studies started in 1954, and France an ...
supersonic airplane even after it became apparent that there was no longer an economic case for the aircraft. The British government privately regarded the project as a commercial disaster that should never have been started. However, political and legal issues made it impossible for either government to pull out.
The idea of sunk costs is often employed when analyzing business decisions. A common example of a sunk cost for a business is the
promotion
Promotion may refer to:
Marketing
* Promotion (marketing), one of the four marketing mix elements, comprising any type of marketing communication used to inform or persuade target audiences of the relative merits of a product, service, brand or i ...
of a brand name. This type of
marketing
Marketing is the process of exploring, creating, and delivering value to meet the needs of a target market in terms of goods and services; potentially including selection of a target audience; selection of certain attributes or themes to emph ...
incurs costs that cannot normally be recovered. It is not typically possible to later "demote" one's brand names in exchange for cash. A second example is
research and development
Research and development (R&D or R+D), known in Europe as research and technological development (RTD), is the set of innovative activities undertaken by corporations or governments in developing new services or products, and improving existi ...
(R&D) costs. Once spent, such costs are sunk and should have no effect on future pricing decisions. So a pharmaceutical company's attempt to justify high prices because of the need to recoup R&D expenses would be fallacious. The company would charge a high price whether R&D cost one dollar or one million. R&D costs, however, and the ability to recoup those costs, are a factor in deciding whether to spend the money on R&D in the first place.
Dijkstra and Hong proposed that part of a person's behavior is influenced by a person's current emotions. Their experiments showed that emotional responses benefit from the sunk cost fallacy. Negative influences lead to the sunk cost fallacy. For example, anxious people face the stress brought about by the sunk cost fallacy. When stressed, they are more motivated to invest in failed projects rather than take additional approaches. Their report shows that the sunk cost fallacy will have a greater impact on people under high load conditions, and people's psychological state and external environment will be the key influencing factors.
The sunk cost effect may cause
cost overrun
A cost overrun, also known as a cost increase or budget overrun, involves unexpected incurred costs. When these costs are in excess of budgeted amounts due to a value engineering underestimation of the actual cost during budgeting, they are known ...
. In business, an example of sunk costs may be an investment into a factory or research that now has a lower value or no value whatsoever. For example, $20 million has been spent on building a power plant; the value now is zero because it is incomplete (and no sale or recovery is feasible). The plant can be completed for an additional $10 million or abandoned and a different but equally valuable facility built for $5 million. Abandonment and construction of the alternative facility is the more rational decision, even though it represents a total loss of the original expenditure—the original sum invested is a sunk cost. If decision-makers are irrational or have the "wrong" (different) incentives, the completion of the project may be chosen. For example, politicians or managers may have more incentive to avoid the appearance of a total loss. In practice, there is considerable ambiguity and uncertainty in such cases, and decisions may in retrospect appear irrational that were, at the time, reasonable to the economic actors involved and in the context of their incentives. A decision-maker might make rational decisions according to their incentives, outside of efficiency or profitability. This is considered to be an ''incentive problem'' and is distinct from a sunk cost problem.
Sunk costs are distinct from economic losses. For example:
Some research has also noted circumstances where the ''sunk cost effect'' is reversed; that is, where individuals appear irrationally eager to write off earlier investments in order to take up a new endeavor.
Plan continuation bias
A related phenomenon is plan continuation bias,
which is recognised as a subtle
cognitive bias
A cognitive bias is a systematic pattern of deviation from norm or rationality in judgment. Individuals create their own "subjective reality" from their perception of the input. An individual's construction of reality, not the objective input, m ...
that tends to force the continuation of an existing plan or course of action even in the face of changing conditions. In the field of aerospace it has been recognised as a significant causal factor in accidents, with a 2004 NASA study finding that in 9 out of the 19 accidents studied, aircrew exhibited this behavioural bias.
This is a hazard for
ships' captains or
aircraft pilot
An aircraft pilot or aviator is a person who controls the flight of an aircraft by operating its directional flight controls. Some other aircrew members, such as navigators or flight engineers, are also considered aviators, because they a ...
s who may stick to a planned course even when it is leading to fatal disaster and they should abort instead. A famous example is the
Torrey Canyon oil spill
The ''Torrey Canyon'' oil spill was one of the world's most serious oil spills. The supertanker ran aground on rocks off the south-west coast of the United Kingdom in 1967, spilling an estimated 25–36 million gallons (94–164 million litres) o ...
in which a
tanker ran aground when its captain persisted with a risky course rather than accepting a delay.
It has been a factor in numerous air crashes and an analysis of 279 approach and landing accidents (ALAs) found that it was the fourth most common cause, occurring in 11% of cases.
Another analysis of 76 accidents found that it was a contributory factor in 42% of cases.
There are also two predominant factors that characterise the bias. The first is an overly
optimistic
Optimism is an attitude reflecting a belief or hope that the outcome of some specific endeavor, or outcomes in general, will be positive, favorable, and desirable. A common idiom used to illustrate optimism versus pessimism is a glass filled wi ...
estimate of probability of success, possibly to reduce
cognitive dissonance
In the field of psychology, cognitive dissonance is the perception of contradictory information, and the mental toll of it. Relevant items of information include a person's actions, feelings, ideas, beliefs, values, and things in the environment. ...
having made a decision. The second is that of personal responsibility: when you are personally accountable, it is difficult for you to admit that you were wrong.
Projects often suffer
cost overrun
A cost overrun, also known as a cost increase or budget overrun, involves unexpected incurred costs. When these costs are in excess of budgeted amounts due to a value engineering underestimation of the actual cost during budgeting, they are known ...
s and delays due to the
planning fallacy
The planning fallacy is a phenomenon in which predictions about how much time will be needed to complete a future task display an optimism bias and underestimate the time needed. This phenomenon sometimes occurs regardless of the individual's know ...
and related factors including excessive optimism, an
unwillingness to admit failure
Face is a class of behaviors and customs practiced mainly in Asian cultures, associated with the morality, honor, and authority of an individual (or group of individuals), and its image in social groups.
Face refers to a sociological concept in ...
,
groupthink
Groupthink is a psychological phenomenon that occurs within a group of people in which the desire for harmony or conformity in the group results in an irrational or dysfunctional decision-making outcome. Cohesiveness, or the desire for cohesiveness ...
and
aversion to loss of sunk costs.
Psychological factors
![Daniel Kahneman (3283955327) (cropped)](https://upload.wikimedia.org/wikipedia/commons/4/4d/Daniel_Kahneman_%283283955327%29_%28cropped%29.jpg)
Evidence from
behavioral economics
Behavioral economics studies the effects of psychological, cognitive, emotional, cultural and social factors on the decisions of individuals or institutions, such as how those decisions vary from those implied by classical economic theory. ...
suggests that there are at least five specific psychological factors underlying the sunk cost effect:
* Loss aversion, whereby the price paid becomes a benchmark for the value, whereas the price paid should be irrelevant.
*
Framing effects, a cognitive bias where people decide on options based on whether the options are presented with positive or negative
connotations
A connotation is a commonly understood cultural or emotional association that any given word or phrase carries, in addition to its explicit or literal meaning, which is its denotation.
A connotation is frequently described as either positive or ...
; e.g. as a loss or as a gain. People tend to avoid risk when a positive frame is presented but seek risks when a negative frame is presented.
* An overoptimistic probability bias, whereby after an investment the evaluation of one's investment-reaping dividends is increased.
* The requisite of personal responsibility. Sunk cost appears to operate chiefly in those who feel a personal responsibility for the investments that are to be viewed as a sunk cost.
*The desire not to appear wasteful—"One reason why people may wish to throw good money after bad is that to stop investing would constitute an admission that the prior money was wasted."
Taken together, these results suggest that the sunk cost effect may reflect non-standard measures of
utility
As a topic of economics, utility is used to model worth or value. Its usage has evolved significantly over time. The term was introduced initially as a measure of pleasure or happiness as part of the theory of utilitarianism by moral philosopher ...
, which is ultimately subjective and unique to the individual.
Experiments have shown that the sunk cost fallacy and loss aversion are common; hence economic rationality—as assumed by much of economics—is limited. This has enormous implications for
finance
Finance is the study and discipline of money, currency and capital assets. It is related to, but not synonymous with economics, the study of production, distribution, and consumption of money, assets, goods and services (the discipline of fina ...
, economics, and securities markets in particular.
Daniel Kahneman
Daniel Kahneman (; he, דניאל כהנמן; born March 5, 1934) is an Israeli-American psychologist and economist notable for his work on the psychology of judgment and decision-making, as well as behavioral economics, for which he was award ...
, who collaborated in this area with
Amos Tversky
Amos Nathan Tversky ( he, עמוס טברסקי; March 16, 1937 – June 2, 1996) was an Israeli cognitive and mathematical psychologist and a key figure in the discovery of systematic human cognitive bias and handling of risk.
Much of his ...
, won the
Nobel Prize in Economics
The Nobel Memorial Prize in Economic Sciences, officially the Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel ( sv, Sveriges riksbanks pris i ekonomisk vetenskap till Alfred Nobels minne), is an economics award administered ...
for his extensive work.
Loss aversion
Many people have strong misgivings about "wasting" resources (
loss aversion
Loss aversion is the tendency to prefer avoiding losses to acquiring equivalent gains. The principle is prominent in the domain of economics. What distinguishes loss aversion from risk aversion is that the utility of a monetary payoff depends o ...
) that may contribute to the sunk cost effect. However,
David Gal
David Gal iProfessor of Marketingat the University of Illinois at Chicago. He is best known for his critiques of behavioral economics, and in particular his critique of the behavioral economics concept of loss aversion. His forthcoming book is tit ...
and Derek Rucker argue that the sunk cost effect cannot be due to loss aversion because there is no comparison of a loss to a gain.
According to the report by ketel, Linde, Oosterbeek and Klaauw, the sunk cost effect on tuition has no impact on student performance. They conducted an experiment in the Netherlands to subsidize college students who had signed up for tutoring. They tried to see if the sunk cost effect would reduce student effort. Although their experiment showed that students who received larger tuition discounts tended to have lower attendance, Low attendance does not imply poor student performance, perhaps test scores are not dominated by attendance, so they conclude that students' grades and performance are not affected by sunk cost effects.
Framing effect
The framing effect which underlies the sunk cost effect builds upon the concept of
extensionality
In logic, extensionality, or extensional equality, refers to principles that judge objects to be equal if they have the same external properties. It stands in contrast to the concept of intensionality, which is concerned with whether the internal ...
where the outcome is the same regardless of how the information is framed. This is in contradiction to the concept of intentionality which is concerned with whether the presentation of information changes the situation in question.
Take two mathematical functions:
# f(x) = 2x + 10
# f(x) = 2 * (x + 5)
While these functions are framed differently, regardless of the input 'x', the outcome is analytically equivalent. Therefore, if a rational decision maker were to choose between these two functions, the likelihood of each function being chosen should be the same. However, a framing effect places unequal biases towards preferences that are otherwise equal.
The most common type of framing effect was theorised in Kahneman & Tversky, 1979 in the form of valence framing effects. This form of framing signifies types of framing. The first type can be considered positive where the 'sure thing' option highlights the positivity whereas if it is negative, the 'sure thing' option highlights the negativity, while both being analytically identical. For example, saving 200 people from a sinking ship of 600 is equivalent to letting 400 people drown. The former framing type is positive and the latter is negative.
Ellingsen, Johannesson, Mollerstrom and Munkammar have categorised framing effects in a social and economic orientation into three broad classes of theories. Firstly, the framing of options presented can affect internalised social norms or social preferences - this is called variable sociality hypothesis. Secondly, the social image hypothesis suggests that the frame in which the options are presented will affect the way the decision maker is viewed and will in turn affect their behaviour. Lastly, the frame may affect the expectations that people have about each other's behaviour and will in turn affect their own behaviour.
Overoptimistic probability bias
In 1968, Knox and Inkster approached 141
horse bettors: 72 of the people had just finished placing a $2.00 bet within the past 30 seconds, and 69 people were about to place a $2.00 bet in the next 30 seconds. Their hypothesis was that people who had just committed themselves to a course of action (betting $2.00) would reduce post-decision dissonance by believing more strongly than ever that they had picked a winner. Knox and Inkster asked the bettors to rate their horse's chances of winning on a 7-point scale. What they found was that people who were about to place a bet rated the chance that their horse would win at an average of 3.48 which corresponded to a "fair chance of winning" whereas people who had just finished betting gave an average rating of 4.81 which corresponded to a "good chance of winning". Their hypothesis was confirmed: after making a $2.00 commitment, people became more confident their bet would pay off. Knox and Inkster performed an ancillary test on the patrons of the horses themselves and managed (after normalization) to repeat their finding almost identically. Other researchers have also found evidence of inflated probability estimations.
Sense of personal responsibility
In a study of 96 business students, Staw and Fox
gave the subjects a choice between making an
R&D investment either in an underperforming company department, or in other sections of the hypothetical company. Staw and Fox divided the participants into two groups: a low responsibility condition and a high responsibility condition. In the high responsibility condition, the participants were told that they, as manager, had made an earlier, disappointing R&D investment. In the low responsibility condition, subjects were told that a former manager had made a previous R&D investment in the underperforming division and were given the same profit data as the other group. In both cases subjects were then asked to make a new $20 million investment. There was a significant interaction between assumed responsibility and average investment, with the high responsibility condition averaging $12.97 million and the low condition averaging $9.43 million. Similar results have been obtained in other studies.
Desire not to appear wasteful
A ticket buyer who purchases a ticket in advance to an event they eventually turn out not to enjoy makes a semi-public commitment to watching it. To leave early is to make this lapse of judgment manifest to strangers, an appearance they might otherwise choose to avoid. As well, the person may not want to leave the event, because they have already paid, so they may feel that leaving would waste their expenditure. Alternatively, they may take a sense of
pride
Pride is defined by Merriam-Webster as "reasonable self-esteem" or "confidence and satisfaction in oneself". A healthy amount of pride is good, however, pride sometimes is used interchangeably with "conceit" or "arrogance" (among other words) wh ...
in having recognized the
opportunity cost
In microeconomic theory, the opportunity cost of a particular activity is the value or benefit given up by engaging in that activity, relative to engaging in an alternative activity. More effective it means if you chose one activity (for example ...
of the alternative use of time.
See also
*
Disposition effect
The disposition effect is an anomaly discovered in behavioral finance. It relates to the tendency of investors to sell assets that have increased in value, while keeping assets that have dropped in value.
Hersh Shefrin and Meir Statman identified ...
*
Endowment effect
In psychology and behavioral economics, the endowment effect (also known as divestiture aversion and related to the mere ownership effect in social psychology) is the finding that people are more likely to retain an object they own than acquire th ...
*
Foot-in-the-door technique
Foot-in-the-door (FITD) technique is a compliance tactic that aims at getting a person to agree to a large request by having them agree to a modest request first.
This technique works by creating a connection between the person asking for a req ...
*
Gambler's fallacy
*
Prospect theory
Prospect theory is a theory of behavioral economics and behavioral finance that was developed by Daniel Kahneman and Amos Tversky in 1979. The theory was cited in the decision to award Kahneman the 2002 Nobel Memorial Prize in Economics.
Based ...
*
Psychology of previous investment
* ''
Thinking, Fast and Slow
''Thinking, Fast and Slow'' is a 2011 book by psychologist Daniel Kahneman.
The book's main thesis is a differentiation between two modes of thought: "System 1" is fast, instinctive and emotional; "System 2" is slower, more deliberative, and mo ...
''
References
Further reading
*
*
* Bade, Robin; and Michael Parkin. ''Foundations of Microeconomics.'' Addison Wesley Paperback 1st Edition: 2001.
* Bernheim, D. and Whinston, M. "Microeconomics". McGraw-Hill Irwin, New York, NY, 2008. .
*
* Kahneman, D. (2011) ''
Thinking, Fast and Slow
''Thinking, Fast and Slow'' is a 2011 book by psychologist Daniel Kahneman.
The book's main thesis is a differentiation between two modes of thought: "System 1" is fast, instinctive and emotional; "System 2" is slower, more deliberative, and mo ...
'',
Farrar, Straus and Giroux
Farrar, Straus and Giroux (FSG) is an American book publishing company, founded in 1946 by Roger Williams Straus Jr. and John C. Farrar. FSG is known for publishing literary books, and its authors have won numerous awards, including Pulitzer ...
, . (Reviewed by
Freeman Dyson
Freeman John Dyson (15 December 1923 – 28 February 2020) was an English-American theoretical physicist and mathematician known for his works in quantum field theory, astrophysics, random matrices, mathematical formulation of quantum m ...
in
New York Review of Books
New is an adjective referring to something recently made, discovered, or created.
New or NEW may refer to:
Music
* New, singer of K-pop group The Boyz
Albums and EPs
* ''New'' (album), by Paul McCartney, 2013
* ''New'' (EP), by Regurgitator, ...
, 22 December 2011, pp. 40–44.)
* Klein, G. and Bauman, Y. The Cartoon Introduction to Economics Volume One: Microeconomics Hill and Wang 2010 .
* Samuelson, Paul; and Nordhaus, William. ''Economics.'' McGraw-Hill International Editions: 1989.
* Sutton, J. ''Sunk Costs and Market Structure''. The MIT Press, Cambridge, Massachusetts, 1991 .
*
Varian, Hal R. ''Intermediate Microeconomics: A Modern Approach. Fifth Ed.'' New York, 1999 .
{{microeconomics
Costs
Cost engineering
Cognitive biases
Behavioral finance
Game theory