Avoid the Sunk Cost Fallacy in Teaching

In his 2022 book, The Voltage Effect: How to Make Good Ideas Great and Great Ideas Scale, economist John List, the Kenneth C. Griffin Distinguished Service Professor of Economics at the University of Chicago, defines the Sunk Cost Fallacy as the idea that one must continue to pursue an idea based on money previously invested. The basic idea is that the money previously spent is already gone and no longer recoverable. As humans we have a tendency to feel like that money is wasted if we decide to abandon the effort we spent that money on, even after the project appears doomed for failure. Too often, people continue to pour good money into a failing effort, because they don't want to waste the bad money they've already dumped into it. Teachers are prone to this same fallacy.

The year was 2019. I sat for the ACT for the first time since I was a junior in high school, way back in 1984. Thirty five years had passed since the one and only time I'd ever actually SEEN the test. Over the years, I'd taught many ACT prep classes, based on what I THOUGHT was on the exam, but I was basing my expectation for what students saw on the test on what other people SAID was on the test. Since 2016, the state of Arkansas was basing part of our school's "grade" on how well our students scored on this test. So I decided to register for the ACT and sit.

I learned some things I didn't know and unlearned some things I thought I knew about the test. I spent the rest of that summer rewriting all my College Algebra and Pre-Calculus curriculum based on what I'd learned. The most important thing I learned was that we assess students so differently than the ACT does, that it should be no surprise they score poorly. The questions are designed completely differently than most math exams I'd always given my kids. I rewrote my tests and assignments using ACT-style questions, so they would be accustomed to the type of problems they would see on the test.

This was all a lot of work. Untold hours really. Every homework assignment and every test. In addition, I added a pre-test and post-test for every lesson using the same style of questions. I could do this because I was the only one teaching these courses at the time, but that also meant I had to invest the time and effort, and even a little money (for a subscription to the platform where I created the assignments,) and do all of it myself.

Though I didn't have much money invested, a lot of time and effort went into this project. 

I had high hopes the cost would be worth it. I didn't expect a monetary return. Instead, what I hoped to see was a return in increased ACT scores in addition to gaining the knowledge students were supposed to get from taking the course. 

So, here I am. This is the fifth year I've used those materials and anecdotal evidence suggests they have made a difference, although not in all cases. But as with all things, students have changed over these five years. Again, not all students, but overall, time spent working on assignments out of class has plummeted. Absenteeism has increased too. And perhaps more than anything, the number of students who can and will actually think and try to figure things out has dropped too. 

Much of this may be due to a Covid hangover, deficits caused when we shut down schools and the rest of the world and sent kids home to get grades whether they worked or not, whether they turned anything in or not, and whether or not they learned anything. But whatever the reason, things that worked with students five years ago may no longer work, or work as well, as they did five years ago.

All that to illustrate how the Sunk Cost Fallacy plays out in teaching. I've already changed my approach and how I deploy the resources I spent so much time creating, hoping to keep using them successfully. But the evidence is becoming clear that they're not as successful as they once were. Before next year, I will have to make some pretty big changes in my approach to homework...AGAIN. As the evidence mounts that students aren't learning as much, or not as many students are learning as much, using these resources, I have to admit that something must change, in spite of the hours of time and the amount of effort I put into creating them. 

If I don't admit it, and worse, if I don't change my approach, I've fallen prey to the Sunk Cost Fallacy, stubbornly clinging to an approach that no longer works, or no longer works well enough, because throwing it out seems like wasting all that time, effort, and money invested in its creation. 

Continuing to use these resources and continue to expect kids to learn from this approach would be the easiest thing for me as a teacher, but it certainly isn't what is best for the kids I teach. We teachers might want to keep using the materials and approach we've grown comfortable with. However, when the time comes that the data show that approach and those materials are no longer effective, or no longer effective enough, failing to adapt does our students a horrible disservice.

We teachers must always be on guard, recognizing the tendency to fall prey to the Sunk Cost Fallacy. We must resist the urge to sit back and reuse those aged lessons, written on yellowing paper from another era. Let's give our kids our very best, and ditch those old materials when they become ineffective, or less effective. Find something newer that will better reach our students so we provide them the best opportunity to succeed that we can.