> The collateral is effectively a claim on the person's future earnings

Back in the Russian empire a person could buy themselves out of serfdom if they could come up with the money… which was difficult for obvious reasons.

And this feels like a modern reincarnation of the system.

It’s categorised as ‘ Unfree Labour’

Its the same too with renouncing citizenship.

If you have federal student loans, you are trapped as being a US serf. And with usurious interest rates, you will never be able to buy your freedom.