The Planning Fallacy

Photo by Jeremy Bishop

I’m approximately three-quarters of the way through Daniel Kahneman’s Thinking, Fast and Slow, and one of the insights that has stuck out to me the most so far is that of the planning fallacy.

The planning fallacy, in short, states that we tend to underestimate how long a task is going to take to complete. From taking out the trash, to writing an essay, to making a meal, we consistently believe that either our most optimistic guess of how long these tasks will take, or the fastest we have ever completed these tasks, are our averages. The planning fallacy does not foresee the natural complications that come up in our everyday lives. As Kahneman notes in the book:

Most of us view the world as more benign than it really is, our own attributes as more favorable than they truly are, and the goals we adopt as more achievable than they are likely to be. We also tend to exaggerate our ability to forecast the future, which fosters optimistic overconfidence.

We all fall victim to the planning fallacy. I’d heard the phrase thrown around before I read it in Kahneman’s book (the book itself has become hugely popular, and has spent 156 weeks on the New York Times Paperback Nonfiction best sellers list as of this writing), but even then, I still tended to believe that my most optimistic guesses and my most impressive times are the norm. They’re not.

Give some thought to the planning fallacy the next time you’re pushed for time; and maybe extend your estimation a little further out. ∎

Benjamin Spall

Benjamin Spall

Benjamin Spall is the co-author of My Morning Routine (Portfolio). He has written for outlets including the New York Times, New York Observer, Quartz, Entrepreneur, Business Insider, CNBC, and more.