People are often overly optimistic when estimating how much time they need to complete a task, be it a school assignment, preparing for a party, or shopping. They plan less time than they actually need and, as a result, fail to complete the task on time. This widely observed phenomenon is termed the planning fallacy.

The lack of sufficient time planning in everyday activities has consequences for the individual, such as failing a class, missing out on a party, or running out of food, all of which can be stress-provoking. Yet the consequences are more severe and long-lasting when it comes to large, public projects.

One of the most infamously delayed and expensive infrastructure projects in U.S. history is the Boston Big Dig (Central Artery/Tunnel Project), which was originally planned to be completed in 1998. It ended up being completed at the end of 2007, about 9 years late. Accompanying the delay were massive financial costs, rising from the initial estimated cost of $2.8 billion to a final cost of over $8 billion, or nearly $22 billion when factoring in interest and related projects.

Many factors may contribute to the overoptimistic estimation of task completion times. One is that people typically focus on positive future outcomes when planning their time. As a result, they disregard past experience of similar tasks that ran over schedule. Instead, they believe that “this time will be different.”

Motivational factors also play a role. Due to self-serving bias, people often blame........

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