In the U.S., you are legally permitted to sell your blood plasma for money, but it's called "donation".
In recent years, the numbers of places set up for donations has skyrocketed, and the amount they're compensating donors has followed suit.
Let's dig in.
Most of the visitors to these donation centers are highly local (A)
People are also more likely to visit donation centers in census block groups (CBGs) that are marked by poverty (B)
Why?
In surveys, donating plasma is predicted by being poor, Black, male, married, having kids, being a student, etc.
In short, people who could really use an extra $150 twice a week for a minimal inconvenience are more likely to donate.
We know this is true because we also have survey data indicating people's stated reasons for donating. Few people are donating altruistically. The top categories by far are about money!
Take a look:
Now, before getting to the juicy result, I want to show one more thing: the impact of COVID stimulus checks on plasma donations.
When the checks went out, the number of visits to plasma donation centers cratered. Donations plummeted because people had the cash they needed.
Now here's the kicker: When plasma donation centers open up, local inquiries into predatory payday and installment loans falls off.
People are seeking credit and donating blood might be how they get it.
If we stratify these trends by age, we see that those with ages less than or equal to 35 - the less well-established - are the ones deciding to use blood plasma donations to offset the need for quick, dangerously high-interest cash, not those greater than 35 years old.
When you look at payday transactions rather than inquiries alone, you get the same picture, albeit with more noise.
Young people really do seem to be defraying the need for credit by selling (sorry, donating!) their blood plasma.
The reasons people sell their are also, evidently, not just to cover essentials.
One of the clearest-cut impacts is that entertainment establishments see an increase in visits after blood plasma donation centers open up.
That last part clarifies something: people would prefer not to get risky, high-interest loans, and they really want a little bit of extra cash. So while they will seek out those loans if push comes to shove, they're more likely to frivolously pursue blood donation.
And that's good! We need blood plasma donations, so if paying people a bit of money makes that possible, so be it.
If we take away that possibility, we can also see that it would make people's lives worse.
How far can we take this? Maybe we can learn from Iran.
In the U.S., about 0.5-1% of the federal budget goes to dialysis:
In Iran, there is a legal, regulated market in selling kidneys and it's such a good deal that the government even pays for the operations. It beats paying for dialysis!
People are more than willing to sell their bodies in different ways that help their fellow citizens, from selling their blood plasma to pawning off a kidney.
Given so many people want to do that, and so many people would benefit from it, the question is, why not?
Frankly, I think we should just do it. The blood plasma donation model has been such a success and it's more than evident that organ payments could be too.
The reason this is hard to explain has to do with the fact that kids objectively have more similar environments to one another than to their parents.
In fact, for a cultural theory to recapitulate regression to the mean across generations, these things would need to differ!
Another fact that speaks against a cultural explanation is that the length of contact between fathers and sons doesn't matter for how correlated they are in status.
We can see this by leveraging the ages parents die at relative to said sons.
The internet gives everyone access to unlimited information, learning tools, and the new digital economy, so One Laptop Per Child should have major benefits.
The reality:
Another study just failed to find effects on academic performance.
This is one of those findings that's so much more damning than it at first appears.
The reason being, laptop access genuinely provides people with more information than was available to any kid at any previous generation in history.
If access was the issue, this resolves it.
And yet, nothing happens
This implementation of the program was more limited than other ones that we've already seen evaluations for though. The laptops were not Windows-based and didn't have internet, so no games, but non-infinite info too
So, at least in this propensity score- or age-matched data, there's no reason to chalk the benefit up to the weight loss effects.
This is a hint though, not definitive. Another hint is that benefits were observed in short trials, meaning likely before significant weight loss.
We can be doubly certain about that last hint because diabetics tend to lose less weight than non-diabetics, and all of the observed benefit has so far been observed in diabetic cohorts, not non-diabetic ones (though those directionally show benefits).
The reason why should teach us something about commitment
The government there has previously attempted crackdowns twice in the form of mano dura—hard hand—, but they failed because they didn't hit criminals hard enough
Then Bukele really did
In fact, previous attempts backfired compared to periods in which the government made truces with the gangs.
The government cracking down a little bit actually appeared to make gangs angrier!
You'd have been in your right to conclude 'tough on crime fails', but you'd be wrong.
You have to *actually* enforce the law or policy won't work. Same story with three-strike laws, or any other measure
Incidentally, when did the gang problems begin for El Salvador? When the U.S. exported gang members to it
Diets that restrict carbohydrate consumption lead to improved blood sugar and insulin levels, as well as reduced insulin resistance.
Additionally, they're good or neutral for the liver and kidneys, and they don't affect the metabolic rate.
Carbohydrate isn't the only thing that affects glycemic parameters.
So does fat!
So, for example, if you replace 5% of dietary calories from saturated fat with PUFA, that somewhat improves fasting glucose levels (shown), and directionally improves fasting insulin:
Dietary composition may not be useful for improving the rate of weight loss ceteris paribus, but it can definitely make it easier given what else it changes.
Those non-metabolism details may be why so many people find low-carb diets so easy!