Understanding and Overcoming the Sunk Cost Fallacy in Business

Written by
Aaron Oh
Last Modified on
April 22, 2024

Let’s say you run a lemonade stand. You buy a fancy lemonade machine, thinking it will make your lemonade taste better. However, after using it for a while, you realise that your lemonade still isn't as popular as the simpler, cheaper one you used to prepare without the machine.

Now, you have a decision to make. Do you keep using the fancy machine because you've already spent a lot on it, or do you go back to the traditional way of making lemonade your customers like?

What's important is to make lemonade that your customers want to buy. So, it's better to return to your old method, even if it means leaving behind the expensive machine. In this case, the money you spent on the machine is a sunk cost. You can't get it back. However, the key is to focus on what's best for your business now, not what you've already invested in. 

Let’s start by understanding what is a sunk Cost.

What Is a Sunk Cost?

Sunk cost is money you've already spent and can't get back. In business, it's like the idea that sometimes you have to spend money to make money. But here's the deal: unlike future costs, such as what you pay for inventory or decide to charge for a product, sunk costs are done deals. They're in the past and won't change, no matter what you decide next. Once the money's spent, it's gone, and it shouldn't steer your decisions moving forward.

Example of Sunk Cost

Let’s say you've spent a bunch of money developing a new product for your business, like an expensive software. Now, let's say it's not doing as well in testing as you hoped. The money you've already spent on developing it is a sunk cost. You can't get it back.

Why Are Sunk Costs Important?

Sunk costs are important in professional decision-making to prevent falling into the sunk cost fallacy. Recognizing that these are past expenditures that cannot be recovered helps guide decisions based on future prospects rather than being unduly influenced by irreversible past investments. This approach ensures strategic planning and resource allocation align with prospective benefits rather than being tied to historical expenditures.

Types of Sunk Costs

There are many types of sunk costs depending on your business. But here are some of the most common ones. 

  • Upfront Capital Expenditures: It's like your initial investments; once you spend them, there's no turning back.
  • Training and Development Costs: Remember those expenses for training your team? Once the training is done, those costs are in the sunk category.
  • Marketing and Advertising Expenses: Consider the money you put into marketing and ads. Once those campaigns are over, those costs stay in the past.
  • Research and Development Costs: These are expenses incurred during research and development. Once that's done, consider it sunk.
  • Legal and Licensing Fees: Payments for licenses or legal stuff fall into this category. Once paid, you can't get them back.
  • Labour Costs: Those salaries and wages you dished out for completed work are sunk costs.

Now, let’s understand the meaning of the sunk cost fallacy.

What Is the Sunk Cost Fallacy?

The sunk cost fallacy or the sunk cost effect refers to our tendency to continue investing in an endeavour, even if it's not providing the expected benefits. In business, you might encounter the sunk cost effect when you're in a situation where you just can't let go of your initial plans, even if they're clearly not working out. 

It's like you're caught in a trap of emotional decision-making and making choices that might not be in your best interest. Here, sunk cost is the money used up during the process and can't be retrieved.

However, sunk cost is never included in your business planning and strategies. These costs won't change, no matter what you decide. So, to make smart decisions, businesses zero in on the costs and revenues directly impacted by the choices they're currently considering.

Why Is Understanding Sunk Cost Fallacy Important? 

Understanding how sunk cost fallacy impacts human decision-making processes is important because it can lead to better decision-making for your business. If you don't recognise this fallacy, you could pour more time, money, or effort into something that isn't worth it just because you've already invested resources. However, when you're aware of how sunk cost fallacy works, you can decide based on what will bring you future benefits instead of being stuck in the past. This knowledge empowers you to make more rational and efficient choices.

What Is an Example of Sunk Cost Fallacy?

There are numerous examples of the sunk cost fallacy in business. To get a clearer understanding, let's explore some examples of the sunk cost fallacy in e-commerce.

Sunk Cost Fallacy Example

Say you're managing an e-commerce online store. You've invested significant money into marketing and promoting a particular product, hoping it would become a best-seller. However, sales have been disappointing and falling short of your expectations. Despite these clear signs, it's tempting to continue pushing the product simply because you've already spent so much on marketing. Here, the idea of cutting your losses and shifting your focus to products that are actually selling might feel counterintuitive, but sometimes it's the smarter move.

Here’s another. In e-commerce, you're no stranger to how quickly trends and customer preferences can change. You might be currently using a platform you've heavily invested in – both in terms of time and money. But what if a better solution is available that can adapt to these rapidly changing trends? Holding onto your current platform purely because of the resources you've already invested could hinder your ability to keep up with the evolving e-commerce landscape.

And then there's the common scenario where your e-commerce inventory is filled with items that aren't selling. You might be reluctant to let go of this inventory because you've already spent a considerable amount to stock it. However, holding onto these products can tie up your capital and storage space. Sometimes, the more practical choice is to find a way to clear this inventory and allocate your resources to products that are in higher demand.

These are just some of the examples. Understanding how it applies to your business can help you make more informed and profitable decisions.

Now that you know the meaning of the sunk cost fallacy and why it's important to understand, let’s find out why the sunk cost fallacy occurs.

Why Does the Sunk Cost Effect Occur?

The sunk cost fallacy can creep into your decision-making for a few reasons:

Loss Aversion: Imagine you've put a lot of effort and money into a project. Admitting it's not working out can feel like a loss, and no one likes to lose. Most people hesitate to give up on the project because it feels like admitting defeat. This phenomenon is rooted in the perception that current costs outweigh a rational assessment of future benefits.

Emotional Attachment: You've poured your heart and soul into a business endeavour. You're emotionally attached to it. It's like a pet project. Letting go can feel like losing a part of yourself, making it hard to move on.


Psychological Commitment: The more you invest in something, the harder it is to let go. It's like a never-ending book you want to finish, even if the plot isn't great. Your psychological commitment can blind you to the reality that it's no longer worth your time or resources.

Sunk Cost Justification: It's like trying to make the best of a bad situation. You might think if you invest just a bit more, it'll all be worth it. You're trying to find meaning or value in your spending, even if it's not logical.

Decision Avoidance: Sometimes, sticking with what you've got is easier. Deciding to cut your losses and move on can be a lot of work. It's like staying in a job you hate because job-hunting is intimidating. So, you stay put, even if it's not in your best interest.

Recognising these psychological factors is the first step to avoiding the sunk cost fallacy. It can help you make more rational decisions, even when it feels difficult to let go of what you've already invested.

How to Avoid the Sunk Cost Fallacy?

You can follow strategies and steps that foster a rational human decision-making process to avoid the sunk cost effect. Here's your guide:

  1. Define the Issue: First, ensure you have a clear problem to solve. Think of it as the core mission. This problem should guide all your decisions; anything that doesn't directly address it is a distraction. It keeps you focused on what's important and helps you brush off unimportant side issues. But this also means you must ensure your business is tracking its cash flows and operating within the planned budget.
  2. Acknowledge Sunk Costs: Begin by recognising that you've already invested time, effort, or money into something and that investment is unrecoverable. The inability to weigh the opportunity costs effectively leads to a skewed human decision-making process, with current costs taking precedence over future gains. So, accept it and move forward. 
  3. Maintain Objectivity: Emotions often blur the lines of rational judgment, especially when you've invested considerable time and effort into a project. Instead of viewing things through rose-tinted glasses and clinging to unwarranted optimism, remember that the failure of a project doesn't define your capabilities as a decision-maker. Take a step back to gain emotional distance from the situation. Delay your decision until you've had time to cool off, which can lead to clearer thinking. The primary goal should always be to make the right decision, irrespective of past investments. 
  4. Prioritise the Future: When making choices, focus on both the present and future costs and benefits rather than dwelling on past investments. Consider how your present decisions align with your future goals and objectives.
  5. Evaluate Opportunity Costs: Instead of fixating on past investments, consider what you could achieve by reallocating your resources elsewhere. Think about the opportunities you might be missing by sticking with sunk costs.
  6. Make Data-based Decisions: When figuring out what to do, it's wise to leave out the stuff you've already spent. Even though it might seem strange initially, using data is the most solid way to make decisions. Have faith in the numbers and analysis while keeping past investments from clouding your judgment.
  7. Adjust Risk Tolerance: Think of your risk appetite as a spectrum. Some people thrive on the high-risk end, believing it leads to the most significant rewards. Others are more risk-averse, seeking the safety of their shell, much like stashing cash under the mattress. To overcome the sunk cost fallacy, consider increasing your comfort with risk. In the grand scheme, incurring sunk costs that won't be recovered is simply part of running a business.
  8. Embrace Feedback: Stay open to feedback and routinely assess your decisions. If a choice isn't yielding the expected results, be willing to adapt and make necessary changes.
  9. Learn from Errors: Understand that making decisions based on sunk costs is a common mistake. Use these experiences as learning opportunities to make better decisions in the future.
  10. Establish an Exit Plan: Outline clear exit criteria before investing in a project or endeavour. Know under what circumstances you'll cut your losses and move on.

Key Differences Involving Sunk Costs

The sunk cost can sometimes be confused with other business costs. That's why it's essential to be aware of these critical comparisons.

Sunk Costs Vs Fixed Costs

Sunk costs represent expenditures from the past that cannot be recovered, such as research and development costs for a failed product or advertising expenses for an unsuccessful campaign. It's crucial to recognise that sunk costs should not factor into future decisions, as doing so can lead to the sunk cost fallacy. This fallacy occurs when individuals or businesses persist with a failing project or venture because they consider the money already invested rather than objectively evaluating the potential future benefits.

Fixed costs, in contrast, are ongoing and remain constant irrespective of changes in the quantity of goods or services produced or sold. These costs, including rent, insurance, and employee salaries on fixed contracts, provide insights into the foundational cost structure of a business and are essential for determining break-even points. Unlike sunk costs, fixed costs are relevant to ongoing business operations and strategic planning.

Sunk Cost Vs Relevant Cost

While you already know what sunk costs are, relevant costs really influence a particular organisational decision. They're crucial because they directly affect the outcome of what you decide to do. Now, unlike those sunk costs, which are like money ghosts from the past that you can't get back, or the fixed costs that just chill, staying the same no matter what, relevant costs are the current and future expenses that come into play when you're making decisions. It's like weighing what you might spend against what you could make, helping you figure out the smartest moves for your business.

Examples include the cost of materials for making a new product, the wages for a particular project, or the expenses tied to promoting a service. Essentially, any cost that plays a direct role in shaping the outcome of a decision is considered relevant. It's like looking at what you might spend and figuring out if it's worth the potential earnings.

Recognising the distinctions between sunk costs, fixed costs, and relevant costs is fundamental for making informed and rational decisions in various business scenarios.

Sunk Cost Vs Sunk Cost Fallacy

Sunk costs, and the sunk cost fallacy are related but distinct concepts. 

Sunk costs are expenditures that have already occurred and cannot be recovered. They are often considered historical data and are irrelevant to future economic decision-making. 

On the other hand, the sunk cost fallacy is a cognitive bias, a psychological trap in which individuals continue investing in a project or endeavour based on past investments, even when it's no longer rational. The fallacy occurs when people let these past expenditures influence their current choices, which may not be in their best interest. It's crucial to recognise sunk costs as historical expenses that should not drive future choices and to be aware of the sunk cost effect to make more rational decisions.

Evaluating How Prone Your Team Is to the Sunk Cost Trap

Assessing if your team falls into the sunk cost trap isn't easy. Scientists have tried using made-up situations to see how people react. But these hypothetical scenarios don't always capture all types of sunk costs, like money, time, effort, and feelings. The big question is: Will you respond the same way during these made-up scenarios as in real life when the stakes are higher? 

Here’s what you need to watch out for - 

The Framing Effect

The framing effect and sunk costs are two psychological concepts that can influence decision-making, often intersecting in the way individuals perceive and respond to information. Think of it as the way you present information to yourself or your team. The words you choose can influence how people see things. If you frame a situation as a potential win, it might lead to a different call than if you frame it as a potential loss.

Now, let's bring in sunk costs - the money you've already spent and can't get back. Sometimes, business owners fall into the sunk cost trap, where past investments affect current decisions. Here's where the framing effect comes in. How you talk about those sunk costs matters. If you see them as a loss, you might be more likely to cut your losses. But if you frame them as an investment or potential gain, you might keep going, even if it's not the smart move.

So, keep an eye out for how you frame things and be mindful of sunk costs. It's all about making decisions based on what's ahead, not just what's in the rearview mirror.

Setting a Cadence to Review Your Strategy

To measure your team’s susceptibility, you may consider setting a cadence to review your strategy. Here’s how:

Review Past Decisions

Look at past projects or initiatives where your team invested resources and assess whether they continued with these projects even when it was clear they were not working as expected. Take note of situations where they should have cut their losses but didn't.

Create a Decision Matrix

A decision matrix is like a scorecard that helps you pick the best option among several choices. You list criteria that are important to you, like cost, effectiveness, and alignment with goals. Then, you rate each option on a scale, add up the scores, and the one with the highest total is likely your best choice. It's a handy tool to make decisions more systematically and pick the option that fits your needs the best.

Analyse Decision-Making Processes

Examine how your team makes decisions. Are they overly focused on past investments? Do they tend to consider future costs and benefits when evaluating their options?

Gather Feedback

Engage in open discussions with your team about their decision-making processes. Encourage them to share their thoughts on how past investments influenced their choices and whether they recognise instances of the sunk cost fallacy.

Use Hypothetical Scenarios

Present hypothetical scenarios that mimic real-life decisions they might encounter. Observe how they approach these scenarios and whether they are prone to factoring in past investments disproportionately.

Monitor and Adapt

Continuously monitor your team's decision-making processes and, if necessary, adapt your approaches and strategies to reduce susceptibility to the sunk cost fallacy. Encourage open communication and learn from past experiences.

Key Takeaways

  • Sunk costs are expenses already spent and unrecoverable. In business, they differ from future costs and should not drive future decisions.
  • Knowing sunk costs helps us avoid the trap of letting past expenses dictate our decisions. It keeps us focused on what's ahead, not what's already spent.
  • The sunk cost fallacy is when we stick with something, even if it's not working, just because we've already put time or money into it. It's like being stuck in a loop of bad decisions.
  • To dodge the trap, we need clear problems to solve, accept what's already spent, stay cool-headed, think about the future, and use numbers, not emotions, for decisions.
  • Check if your team falls for the trap by looking at past choices, creating scorecards for decisions, watching how they decide, talking about past choices, and imagining tricky situations.

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About the author
Aaron Oh
is a seasoned content writer specialising in finance, insurance and tech industries. With a writing history at S&P Global, EdgeProp, Indeed, Prudential, and others, Aaron leverages finance knowledge and business insights to help businesses improve productivity and performance.
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