My original comment (above) made it pretty clear that I believe we should be doing everything we can to ensure people don't have to make these kinds of choices.

But the way to do this is by adding new, better options, not by restricting existing, 'bad' options.

Sure, but that is an utopia that I hardly believe we will ever reach. No question hundreds of years in the future.

Lets allow people to get exploited because it might not be a problem in the distant future? Or, work from both ends. By restricting bad options at the same time as we add, best we can, the good options.

The whole point of the scenario was that there are no good options.

We shouldn't allow people to get into a situation where they have to choose between losing a kidney and their children starving.

But - if someone is in that situation - it makes absolutely no sense not to let them decide which option they find least worst.

By doing that, you're only making things worse.

Your argument makes sense when you view such transactions as a decision problem with a single actor and no temporal element.

But such transaction happens within a lifelong game with at least two players. Changing the rule of the game can influence their game tree and their behavior, far before they get into a situation where the change applies.

For the kidney trade, banning it might discourage potential organ-buyers from 'check-mating' people into selling their kidneys. It also might nudge parents to work harder since they have one less things to sell off.

I acutually have no opinion over banning organ trade. I'm just saying that it could make some sense.