Original:  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 and privately holds information about the undesirability of abandoning a project, it may be rational to display the sunk cost effect and persist with the project. Fallacy effect The bygones principle does not accord with real-world behavior. Sunk costs do, in fact, 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.” Others buy expensive gym memberships to commit themselves to exercising. 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. 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 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. In an everyday example, a family may purchase tickets to a baseball game and find after several innings that they are not enjoying the game. Their options at this point are to: Accept the waste of money on the ticket price and watch the remainder of the game without enjoyment; or Accept the waste of money on the ticket price and leave to do something else. The economist will suggest that, since the second option involves suffering in only one way (wasted money), while the first involves suffering in two (wasted money plus wasted time), option two is preferable. In either case, the ticket-buyer has paid the price of the ticket so that part of the decision should no longer affect the future. If the ticket-buyer regrets buying the ticket, the current decision should be based on whether they want to see the game at all, regardless of the price, just as if they were to go to a free baseball game. Many people, however, would feel obliged to stay for the rest of the game despite not really wanting to, perhaps because they feel that doing otherwise would be wasting the money they spent on the ticket. They may feel they have passed the point of no return. Economists regard this behaviour as irrational. It is inefficient because it misallocates resources by taking irrelevant information into account. 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 of a brand name. This type of marketing 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 (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 is fallacious. The company will charge market prices whether R&D had cost one dollar or one million dollars. However, R&D costs, and the ability to recoup those costs, are a factor in deciding whether to spend the money on R&D or not. The sunk cost effect may cause cost overrun. 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;
Revised:  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 his company. Or, if he holds 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 accord with real-world behavior. Sunk costs do, in fact, 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.” Others buy expensive gym memberships to commit themselves to exercising. 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. 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 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. In an everyday example, a family may purchase tickets to a baseball game and find after several innings that they are not enjoying the game. Their options at this point are to: Accept the waste of money on the ticket price and watch the remainder of the game without enjoyment; or Accept the waste of money on the ticket price and leave to do something else. The economist will suggest that, since the second option involves suffering in only one way (wasted money), while the first involves suffering in two (wasted money plus wasted time), option two is preferable. In either case, the ticket-buyer has paid the price of the ticket so that part of the decision should no longer affect the future. If the ticket-buyer regrets buying the ticket, the current decision should be based on whether they want to see the game at all, regardless of the price, just as if they were to go to a free baseball game. Many people, however, would feel obliged to stay for the rest of the game despite not really wanting to, perhaps because they feel that doing otherwise would be wasting the money they spent on the ticket. They may feel they have passed the point of no return. Economists regard this behaviour as irrational. It is inefficient because it misallocates resources by taking irrelevant information into account. 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 of a brand name. This type of marketing 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 (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 is fallacious. The company will charge market prices whether R&D had cost one dollar or one million dollars. However, R&D costs, and the ability to recoup those costs, are a factor in deciding whether to spend the money on R&D or not. The sunk cost effect may cause cost overrun. 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;
Edit intent: meaning-changed