> Rank Location 1 Algeria 2 Iraq 3 Yemen 4 Myanmar 5 North Korea 6 Afghanistan
I am hoping you are not attributing violence and instability in some of these countries to lead based gasoline. Sure, there may be correlation, but these places are centuries old. There are many factors like culture, religiosity, socio-economic status , history, contemporary culture, so on and so forth.
No I’m not. I still find it to be an interesting correlation worthwhile for further examination. Would you rule it out entirely?
Before there were studies like the ones mentioned in the article people wouldn't believe it for cities like Flint in the states neither. I’m still not 100% convinced that there is causation. But if those studies are no fakes and hold up for repetition then I’d argue that there is some truth behind the theory
Yes, unless you have a secret way of ruling out the other much more likely factors (i.e what GP mentioned).
You could argue that those countries still use leaded gasoline because the political turmoil/violence within them makes folks prefer the cheaper, easier fuel to produce.
Is it cheaper or easier to produce? The industrial process is difficult and hazardous. An alternative anti-knock agent is ethanol, which you can make at home. Originally, leaded gasoline was pushed by GM because they held the patents.
Ethanol production competes with citizens for food (how many of those countries using leaded gas have experienced famines recently?). Adding it to gasoline results in a fuel with ~30% less energy per unit, so you'd have to produce more gasoline to get an equivalent amount of energy.
I've read a study (can't find the link, sorry) comparing the cost of various ways of boosting the octane rating. Of all the alternatives (TEL, aromatics, alcohols, ethers, MMT, etc.) TEL was the cheapest.
I wonder what fraction of TEL consumption worldwide is due to aviation vs. these few remaining countries that use it in motor gasoline?
It seems plausible that high environmental lead levels contribute (with at least a small effect size) to violence and crime.
If a lead-free environment is already violent and insecure, would you expect adding environmental lead to make it less violent, more violent, or the same?
Yeah, which is why the data is backed up by multiple panel analyses that actually make the argument for causation. The US data shows that crime rates rose like clockwork approximately ~20 years after leaded gasoline is used en masse, and drops ~20 years after it was banned.
Different states introduced and subsequently banned leaded gasoline on different schedules, so this was a 'natural' experiment, unless you can think of some other causative factor that precisely explains the timing of the rise and fall of crime.
I don't understand this content-free 'correlation does not equal causation' argument.
Sure, in the absence of other evidence and a mechanism of action, we should have healthy skepticism, but it's known how lead affects brain development, particularly how it screws up development of the frontal cortex, lowering both intelligence and social inhibition.
Re natural experiment: what about the water pipes? Were they exchanged as well? I don’t think you can see this as natural experiment unless other factors are equal
TFA discusses a natural experiment with water pipes. Cities near lead production centers tend to have lead pipes, so they compared cities with that characteristic and acidic water (which leaches lead into the water) and such cities without acidic water. The study found a strong effect.
Yeah, which is why the data is backed up by multiple panel analyses that actually make the argument for causation. The US data shows that crime rates rose like clockwork approximately ~20 years after leaded gasoline is used en masse, and drops ~20 years after it was banned.
Did they also account for changes in how crime rates are reported over time?
One would have to account for hundreds of different variables before you could ever conclusively prove a connection between lead and crime.
It would be impossible to 100% conclusively and with absolute precision determine the exact connection between the two. That doesn't mean it's not the best available theory at the moment, that fits the most data. There are international, interstate, and even local level analysis all pointing to the same thing. There are longitudinal studies on children pointing to the same thing. And there are established and direct casual mechanisms in the brain biology that explain it. So what does waving a hand and saying "Nah nah can't prove it" do? By your standards do we have zero knowledge on all sociological matters, since it's impossible to design and implement a perfectly controlled study?
>Did they also account for changes in how crime rates are reported over time?
The Bureau of Justice Statistics conducts a yearly survey asking people about the crimes they were a victim of in the past year regardless if the crimes were reported. The Bureau of Justice survey shows a much more dramatic reduction in crime than if you just look at reported crimes.
Not to mention that a society with more violence/unrest (for whatever reason) may be less likely to have a government with a functioning regulatory system, i.e. unrest may cause gasoline to remain leaded rather than the other way around.
I am hoping you are not attributing violence and instability in some of these countries to lead based gasoline. Sure, there may be correlation, but these places are centuries old. There are many factors like culture, religiosity, socio-economic status , history, contemporary culture, so on and so forth.