Comment by Gibbon1 | Hacker News Reader

Comment by Gibbon1 | Hacker News Reader

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I think demise of cities was due to being starved for capital, redlining, automobiles, and crime due to lead pollution.

Post war capital was invested in suburbs instead of urban cores which then decayed.

Redlining also meant urban areas inhabited by minorities were cut off from capital. Not only couldn't minorities get loans, but even their often white landlords couldn't.

Automobiles allowed workers to locate their families in cheap suburbs while sucking at the corporate teat in Urban Cities. At least until too many people spoiled a good thing as auto congestion built up.

Leaded gasoline caused brain damage which effected dense urban areas the most, resulting in high crime rates.

The last 40 years has seen a reversal of that at least for some urban cities. Capital is being invested in cities. Hard redlining is gone. Replaced by jacking minorities with exploitative loan products. Suburban congestion has made suburbs much less attractive. The decline of lead pollution means urban cities are again 'safe'.

Lead pollution hypothesis is one of many plausible explanations and shouldn’t be presented as fact.

True, but there is recent evidence that is pretty much the gold standard for a perfect randomized experiment where they tracked children with high blood levels who did and did not receive interventions to lower it. Those receiving treatment committed violent crimes at a far lower rate than those who were exposed but had no intervention. https://pubs.aeaweb.org/doi/pdfplus/10.1257/app.20160056

Are you saying that inner city crime is by brain damage, rather than by living in desperate circumstances?

Yes. Read the paper. All confounding factors are controlled. It is the holy grail of causality.

What about possible unknown unknown confounding factors?

Yes. Desperate circumstances contributed (and still do) but there is ample evidence that the huge uptick in urban crime in the 60s and 70s was due to leaded gasoline.

Are you saying the rectangle’s area is caused by its length, rather than its width?

Vaguely relevant: there's reason to believe that the current Central American gang violence epidemic, which is driving the migrant crisis at the US/Mexico border is also due to leaded gasoline. Central America didnt' eliminate leaded gasoline until the 2000s.

Many european countries eliminated unleaded gasoline during the same time. And crime rates dropped much sooner.

I'd say unleaded gasoline is not the most important factor. For Europe, I think it was drug use.

Can you elaborate?

Leaded gasoline was banned around the year 2000 in both the EU and Mexico. At that time, crime rates were dropping significantly in Europe, without elapsing 18-25 years.

Also, European countries have some of the lowest crime rates in the world. If the young of the 2000s were under its influence, the effect is not large(not larger than 1-2 homicides per 100K people).

I believe that drug abuse during the 80s and 90s was the culprit of high crime rates in Europe. People addicted to drugs(heroin, crack, cocaine, etc.) committed lots of crimes. In the late 90s and early 2000s, Europe managed to lower drug abuse and then crimes dropped. For Mexico, there is likely another explanation. Like drug trafficking for instance.

Having said this, I think leaded gasoline has adverse effects on public health. I believe it can create mental problems on people.

However, not everyone exposed to leaded gasoline will develop those problems. And among those affected, not all of them will become criminals only because of lead poisoning. Therefore, I don't think that the majority of criminals during the 90s were so because of leaded gasoline. I think that other factors were more important, like drug abuse.

That seems like a weird analysis. Leaded fuel was available but not exactly widespread in EU in 1999. Their timeline was similar to the American timeline: 1973-1996 phaseout for US, 1976-2000 phaseout for Europe.

Can you talk about how increasing crime (prior to the drop you talked about) is related to increasing drug use, any numbers behind that?

I think the lead hypothesis suggests that lead exposure inhibits impulse control, which can manifest as higher rates of violent crime but can also manifest in other ways.

Presumably, desperate circumstances will make it manifest as violent/property crime. But there are probably other manifestations that slide under the criminal justice radar too, like domestic violence and general aggression/bullying among communities in less desperate circumstances.

During the 2001 recession, 2008 financial crisis there were dire predictions that violent crime would go up. Misc property crime went up a bit and violent crime didn't. Violent crime perpetrated by young urban males continued to decline as well. In the face of high rates of unemployment.

Personally I think cultural normalization of violence and quality of policing plays a role in the level of violence. But socio-economic factors really don't.

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