Well, after arguing that it's impractical to run RCTs I guess it's time for a bit of a 'climb-down', because this is a really great idea. I could definitely see this working in a place like the USA, where you have lots of big States with diverging political views.

I wonder what would be the best way to implement something like this? Just spitballing, but what about Federal grants to partially fund the 'treatment' States (with non-participating States acting as controls), with the policy issue and various 'treatments' negotiated between the Fed and State level? And then after that, States sign on using a mechanism similar to California proposition voting during State elections maybe?

Or maybe even push it down to a local government level? I seem to remember somewhere in the US conducting trials of basic income around the 50s or 60s. Maybe there's a model there...