I disagree entirely. The problem with black markets is they function because the money they trade in has real world value. If you taint significant sums so the

I disagree entirely. The problem with black markets is they function because the money they trade in has real world value. If you taint significant sums so they can't be used to buy assets (3k is a lot of money for a single transaction, thanks) you make it harder to benefit from crime. And I don't understand why you're explicitly defending tax evading smallholders. Because farms? Even smallholders can declare and deduct expenses. On your first point, some countries allow asylum seekers to work, and even if they don't, some tax systems allow them to declare income even if they're not really allowed to have any. I'm definitely in favour of making sure everyone works to the same rule, so everyone can live honestly. Cash-in-hand work has to die.