1. Roll out law to 2%, look for any obvious unintended effects (like we check for crashes)
2. Roll out law to 50%, study for effectiveness. Is the intended positive effect happening in the experiment population? Any effect on the control population?
3. Finally, roll out law to 100% and keep monitoring.
4. Be ready to roll back to 0% if failures seen at any stage.
5. Be ready to apply a zero day patch after it's at 100% if edge cases are found.
But, we don't do any of this! Lawmakers make a law and yolo it into production on a fixed date, and it's often impossible to roll it back or modify it.
California is the experimental group.
Even the Constitution. It was intended to be revisited for appropriateness and currency every 20 years.
Instead, a significant number of people, including some on the Supreme Court, believe that the Founding Fathers[1] could speak no wrong words and that the Constitution is the perfect document, to be taken at its word, with no deviation, until the end of time.
[1] Pop Quiz: "How old were the Founding Fathers when they signed the Declaration of Independence and crafted the Constitution?" You'd be forgiven for thinking they were world-weary, wizened old men. In fact, the majority were under forty. Indeed, it was also signed by a sixteen-year-old, a 21-year-old, two 26-year-olds, a 27-year-old, and a 29-year-old.
Once past your childhood, you had a good chance of making it to 60 at least.
American politics might have bigger problems at the moment, but under normal circumstances, I consider this pretty important. I'm not sure what the solution is, but an expiration date on nearly all laws comes to mind as a start to an interesting discussion on the matter.