The population thing is pretty elementary. If population is flat to declining, then growth is demand constrained.

There are some areas where you could uncap growth by cutting regulation, but they're not this. The #1 one I'm aware of is housing construction in high cost metros.

I see your point, but not totally buying it. The US innovates for a global population, one that’s still growing.

The best way to infer causality is through experimentation. If regulation does go away, we’ll measure and learn if it actually worked.

Reagan cut regulation, and manufacturing still left, quick as ever.

I assume that is due to larger trends. Population growth has slowed considerably and there's more competition than ever. Worldwide fertility rates have dropped from 4.7 to 2.3 in the last 75 years, and in that time the U.S. share of world GDP dropped from about 50% to 25%.

My two cents: We may be already be in uncharted economic territory with regards to shrinking workforces, retirees, pollution, etc. How much of our economy is dependent on growth? We may find out. Places like Japan, Korea and Europe are leading the way. Ponzi schemes won't work forever. The world is getting smaller and older. And evening out. There's less room for arbitrage. Innovation is coming from all directions. Technology can still increase productivity. But it could also put masses of people out of work, leaving not enough demand for the latest and greatest. That, and a pie that is no longer growing, could cause a lot of social friction.

>We’ll measure and learn if it actually worked.

I don't believe that will happen, and I base that belief on all my decades of watching American politics. Bureaucrats may do this (I personally work with ones who do), but politicians generally do not. And the current administration definitely does not care about actual numbers.