11 Laws of the Universe

We present to you 11 mental models and principles for productivity, management, and decision-making:

Laws of time, tasks, and productivity

1. Parkinson's Law
   Work expands to fill the time you allocate to it. Shorten the deadline, shorten the task.
2. Hofstadter's Law
   Everything takes longer than you expect, even when you take Hofstadter's Law into account.
3. The Pareto Principle or 80/20 Rule
   Roughly 80% of the results come from 20% of the effort.
4. Brooks's Law
   Adding more people to a project that is already behind schedule will delay it even further because we underestimate the cost of coordination.

Decisions, behavior, and competence

5. Hanlon's Razor
   Never attribute to malice what can be adequately explained by carelessness or stupidity.
6. The Peter Principle
   People are promoted until they reach a job at which they are incompetent, and then they remain there.
7. Hick's Law
   More options mean slower decisions. Simplify the menu and make decisions faster.
8. The Dunning–Kruger Effect
   The less you know, the more you overestimate how much you know.

Systems analysis and understanding

9. Goodhart's Law
   When a measure becomes a target, it ceases to be a good measure.
10. Occam's Razor
    The simplest explanation is usually the correct one.
11. Chesterton's Fence
    Do not tear something down until you understand why it was built in the first place.