The sunk-cost fallacy (SCF) occurs when an individual makes an investment with a low probability of a payoff because an earlier investment has already been made. It is considered an error because a rational decision should not factor in now-irretrievable investments, as they do not affect current outcome likelihoods. Previous research has measured the tendency to commit the SCF by using hypothetical scenarios in which participants must choose to make a future investment or not after making an initial investment. There are many theories as to why people commit the SCF. Loss aversion, which is the preference for uncertain over certain losses, may be related to the SCF. Dual-process theory, which views decision-making in terms of a fast, automatic process called system 1 and a slow, deliberate process called system 2, may also help to explain the SCF. In Experiment 1, participants were asked to complete a sunk-cost questionnaire in which the initial-investment types and amounts varied. They also completed an endowment-effect task as a measure of loss aversion. The SCF was committed most often when the initial investment was large compared to small and most often with money, less with time, and least with effort. There was an interaction effect in which small differences were seen in the SCF between time, effort, and money when the initial investment was small, and differences grew larger as the initial investment increased. Loss aversion displayed a non-significant negative relation with the SCF. In Experiment 2, participants completed a sunk-cost questionnaire in which they were asked to respond as they normally would and then from the perspective of a fictional person described as a logical decision maker. In cases in which they committed the SCF, they were asked to indicate why they continued to invest. They also completed a risky-lottery loss-aversion task. As seen in Experiment 1, the SCF was more likely when initial investments were greater and occurred most when the initial investment was money, less when it was time, and least when it was effort. Loss aversion had a significant but small negative relation with SCF scores. There was no effect of perspective taking. It may be that the SCF is simply due to the over-application of the personal rule “don't waste”, as not wanting to be wasteful was the most-common reason participants gave for why they committed the SCF.



College and Department

Family, Home, and Social Sciences; Psychology



Date Submitted


Document Type





sunk-cost fallacy, loss aversion, perspective taking, behavioral economics, dual process theory, prospect theory, decision making

Included in

Psychology Commons