The result is that good times correlate with more labor laws, but the causation goes the other way.
For example, social security pays benefits based on past income rather than a fixed or need-based payment, and the social security tax is a flat rate with an income cap, making it one of the most regressive taxes short of a poll tax. Meanwhile the amount of political corruption and mafia involvement in labor unions in the era of the Wagner Act makes it highly suspicious that their original purpose or effect was actually labor protection.
And to the extent that there were new actual labor laws, they were often largely symbolic or ineffectual. For example, the original federal minimum wage only applied to jobs in interstate commerce, which at the time actually meant interstate commerce. By contrast, many of the actually-meaningful state-level minimum wage laws were passed during the boom times in the 1920s.
Most of the meaningful labor and safety regulations we have came out of the economically prosperous period of the 1950s and 60s, e.g. that's when the federal minimum wage was extended to other workers, and then extended further in the economically prosperous period in the 1990s.
I'm not sure your hypothesis fits reality
Affordable Care Act (and subsequent non-repeal), disclosure requirements for executive pay ratios, very long list of state-level measures (which is where most of this actually happens in general).
This is just 2018: https://www.littler.com/publication-press/publication/ready-...
The current era is also a bit odd because Wall St. and a handful of megacities are booming but real wages in general haven't risen much, the rust belt is still falling apart, suffering from the opioid epidemic, etc. So it's not that surprising to see lots of new labor laws in places like California while other places are more worried about saving local businesses.
> Just recently the Supreme Court ruled that forced arbitration was legal and we are at some of the highest profits and productivity ever.
There are always counterexamples, and that one is from the courts rather than the legislature.
> Those protections weren't going up during the boom cycles in the 90s either.
Arbitrary sample of state-level changes (1990 and 1998), BLS has the whole set if you're interested:
Hell, I gave less than two weeks notice at my last job and was privately approaches by multiple coworkers asking me if I was worried about the company black listing me. When we have companies lay off/fire people though, no one bats an eye at them being immediately walked out the door. Stating that labor rights have been going up just seems willfully ignorant based on the actual results in the economy
That's just assuming the causation goes the other way again. If the labor rules instead are pricing smaller businesses out of the market leading to business consolidation that gives capital more power over labor, you would expect just what we see.
It also doesn't make a lot of sense to expect a lot of labor laws to increase wages regardless. If you pass a law requiring maternity/paternity leave, that benefits the employee but raises costs for the employer who has to find and pay a temporary replacement. The expected result of that is to suppress wages rather than increase them -- the money has to come from somewhere and most businesses don't have huge margins.
That determines the region, not the town. Equalize the labor cost and the optimal location may move significantly, e.g. to border the city from a different side. It would tend to move it from an area with low labor costs to an area with higher labor costs (and therefore cost of living) but closer proximity to customers or transport infrastructure. And making 50% more in a town with double the cost of living is no raise.