So, with infinitely long supply chains and very complicated products of unclear provenance, and people who care more about looking moral than being it… not well.
Information asymmetry is not a problem well handled by default in a standard free market, I think. But all you need is certification! If only companies that don't make things in sweatshops are allowed to brand with Not Made In A Sweatshop stickers, the consumer can naturally prefer those. Of course if anyone can make up their own certification and stick it on a product, consumers get confused and can't tell what's legit.
As an example, consider the success of nutrition labelling (nutrition facts). It's much harder to make and sell food that only LOOKS healthy, calorie-wise, when anyone can check pretty easily.
(Disclaimer, the actual Nutritional Facts on the back are more useful, but as the endless debate about "what is actually good vs not good" might indicate, it's far from a Source Of Truth, and in many cases can likely be gamed as well. Similarly to how even if a news article lists all their funding sources, an average person probably doesn't care/might still not get much information from it/might still be mislead by crafting of that fact. I don't say this to encourage gatekeepers, but to call out that I'm not sure the current approaches are effectual)
Post-factum-edit: To the downvoters, before this post disappears, at least tell me where I'm wrong. US Obesity rate is through the roof[0]; and while this absolutely has socioeconomic roots, that's the crux of my statement: we're not addressing root causes, and are thus lacking many of the outcomes we'd want.
Have you read the back of a package recently? This is directly from some nuttella in the pantry:
"Energy 332KJ Daily Intake 4%"
in one point font gray on white "Per 15 gram serve."
Average adult diet of 8700KJ.
On other side of the package: 220g net.
So the actual energy in the package is 4869KJ. This is by far not the worst. I have seen chocolates where the "serving size" was two squares.
You can count on any regulation that is bad for business to be subverted to the point of uselessness.
> Serving Size: 2 Tbsp unpopped (makes about 4.5 cups popped)
> Servings Per Bag: about 2.5
> Calories (2 Tbsp unpopped): 170
> Calories (1 Cup popped): 35
How many calories per bag?
The worst thing is, it fooled me. I wouldn't've bought it if I'd realized the answer was about 400.
Can you name a more moral economic system than that?