A controlled comparison of different deadline structures found a clear, consistent hierarchy: externally imposed, evenly spaced deadlines produced the best outcomes, self-chosen (but binding) deadlines came in second, and complete freedom with only a final deadline produced the worst results — directly challenging the common assumption that more autonomy and less external structure should generally produce better self-directed outcomes. This suggests that for many people, structure imposed by an outside system compensates for a real, predictable weakness in self-imposed commitment, rather than simply being a less-preferred but equally effective substitute.
A separate, real-world program applied the same underlying insight to a completely different behavior — retirement savings — with striking results, by removing the need for ongoing willpower entirely rather than trying to strengthen it: committing in advance to a structural rule, rather than relying on repeated future decisions, consistently outperforms relying on repeated self-control.
Dan Ariely ran an experiment across three sections of his own class, each requiring three papers over the semester: one section had evenly spaced mandatory deadlines set by Ariely, one could set their own binding deadlines in advance, and one had complete freedom with only a single final end-of-term deadline. The externally imposed, evenly spaced group performed best; the self-chosen deadline group performed second-best; the total-freedom group performed worst. Separately, economists Richard Thaler and Shlomo Benartzi designed a real retirement-savings program, "Save More Tomorrow," letting employees commit in advance to automatically raising their contribution rate whenever they received a future pay raise, removing the need to make a fresh willpower-based decision each time. At companies that implemented it, participating employees' savings rates climbed from roughly 3.5% to about 13.5% over several years.