This refers to the tendency to underestimate the amount of time it will likely take them to complete a task. Due to unwarranted optimism about their ability to finish a task, people are more likely to postpone the completion of the task until later than try to complete it well ahead of time. At the same time, a third-party observer is likely to be pessimistic and thus overestimate the amount of time it will take to complete a particular task. The planning fallacy was first proposed by Israeli-American psychologists Daniel Kahneman and Amos Tversky in their 1979 paper “Intuitive prediction: biases and corrective procedures”.
