Timelines and the Planning Fallacy


We frequently plot our goals onto timelines. But, in doing so, we often succumb to the planning fallacy.

In the book Thinking Fast and Slow, Daniel Kahneman explains that people have a tendency to underestimate how much time is needed to complete a task, like in a home renovation. “When forecasting the outcomes of risky projects…[we] make decisions based on delusional optimism rather than on a rational weighting of gains, losses, and probabilities.” That’s why it is crucial that we attach our goals to realistic timelines. Realistic timelines can be ascertained by comparing our goals with a reference class of past, similar projects.

In Lean In Sheryl Sandberg suggests that we set our goals according to an 18-month timeline. A year is often not enough time. We tend to over-estimate what we can accomplish in a year. But, two years feels too far away.