Sunk Cost Fallacy: Understanding the Psychological Trap

The sunk cost fallacy is a common cognitive bias that can lead individuals to make irrational decisions based on past investments, rather than objectively evaluating the current situation. This phenomenon often occurs when people continue to pursue a course of action or project simply because they have already invested time, money or effort into it, even if it no longer makes sense to do so. Understanding the sunk cost fallacy is essential for making more rational and informed decisions.


The concept of the sunk cost fallacy was first formally recognized by economists and psychologists in the 1970s. Prior to this, the idea that people could be influenced by past investments was not widely studied or understood. Researchers began to explore how individuals often have a hard time letting go of sunk costs, even when it is in their best interest to do so.

One of the earliest studies on the sunk cost fallacy was conducted by psychologists Daniel Kahneman and Amos Tversky. In their research, they found that individuals were more likely to continue gambling after losing money, simply because they had already invested a significant amount. This behavior contradicts the rational economic theory that people should make decisions based on future costs and benefits, rather than past investments.

Understanding the Psychological Trap

The sunk cost fallacy occurs when individuals base their decisions on the amount of resources they have already invested, rather than on the potential outcomes of continuing the investment. This can lead to poor decision-making and increased financial loss in the long run. For example, someone who has already spent a significant amount of money on a failing business may be reluctant to cut their losses and move on, simply because of the sunk costs involved.

Recognizing the sunk cost fallacy is the first step in avoiding its pitfalls. By acknowledging that past investments should not dictate current decisions, individuals can more objectively evaluate their options and make more rational choices. This involves considering the relevant factors at play in the present moment, rather than being influenced by past sunk costs.

In order to overcome the sunk cost fallacy, it can be helpful to reframe the decision-making process. Instead of focusing on what has already been invested, individuals should consider the potential future outcomes of their choices. This shift in perspective can help to break the cycle of irrational decision-making and lead to more successful outcomes in the long term.

Overall, understanding the sunk cost fallacy is crucial for making informed and rational decisions in both personal and professional contexts. By being aware of this cognitive bias and its potential impact, individuals can avoid falling into the trap of basing decisions on past investments, and instead focus on what will lead to the best outcomes moving forward.