8 laws · Productivity & time laws
Laws of productivity and time management
Why work expands, why everything takes longer than planned, and why the important task keeps getting pushed to tomorrow — plus the fixes that actually stick.
Parkinson's Law
Work expands to fill the time available for its completion.
Hofstadter's Law
It always takes longer than you expect, even when you take into account Hofstadter's Law.
Carlson's Law
Work done in one continuous block takes less time and energy than the same work done in interrupted pieces.
Illich's Law
Beyond a certain number of hours, productivity falls and can turn negative — more work stops producing more results.
Laborit's Law
People naturally avoid unpleasant tasks and seek immediate rewards — so the hardest, most important work gets postponed.
Ninety-Ninety Rule
The first 90% of a project takes 90% of the time; the remaining 10% takes the other 90%.
Parkinson's Law of Triviality (Bikeshedding)
Groups spend disproportionate time on trivial issues and too little on complex, important ones.
Premack Principle
A preferred activity can be used to reward a less preferred one — do the hard thing first, then the enjoyable thing.