From the abstract of “An Economic Model of the Planning Fallacy,” (pdf!) by Markus Brunnermeier, Filippos Papakonstantinou, and Jonathan Parker:
People tend to underestimate the work involved in completing tasks and consequently finish tasks later than expected or do an inordinate amount of work right before projects are due. We present a theory in which people procrastinate because the ex-ante utility benefits of anticipating that a task will be easy to complete outweigh the average ex-post costs of poor planning. … We test our theory using extant experimental evidence on differences in expectations and behavior. We find that reported beliefs and behavior generally respond as our theory predicts.
It’s nice to think that turning in a book manuscript almost four years after it’s due might be the result of the interaction between ex-ante utility benefits and average ex-post costs. Rather than, you know, some kind of deep character flaw.