7 ms·

Lead Water Pipes in 1900 Caused Higher Crime Rates in 1920?

147 points by curtis 11y ago

astrodust 11y ago
No doubt we'll find an unfortunate blip in twenty years in Flint.
- bluedino 11y ago
  Speaking of Flint (and Chicago as well), why are murders/shootings at new highs when they went down in the 90's like in every other area? Did they starting using lead paint again in the 80's?
  - sudojudo 11y ago
    Pretty sure the up-tick has more to do with socioeconomics and the drug war than anything else. I don't have any sources at hand, so take this with a grain of salt. But, I've often seen it argued that Reagan era drug policies were detrimental to poor minorities, especially black men. The problems we see today are the trickle-down effects (couldn't resist) of turning an entire generation of fathers into disenfranchised criminals.
    - trhway 11y ago
      yes, one can google a lot on crack cocaine and its correlation with crime back then and later.
    - astrodust 11y ago
      Throwing a generation of fathers in jail for trivial offenses not only erodes confidence in the judicial system, it leaves children without a role model. Like if dad's in jail, who cares if you end up there eventually. Prison isn't a deterrent any more. In some communities doing time is just part of growing up.
ori_b 11y ago
> Cities that used iron pipes, in contrast, had higher rates of death from circulatory disease, cancer, and cerebral hemorrhage. We know of no scientific literature to motivate these latter relationships. Is it possible that this is just because people weren't dying of other things first?
- toomuchtodo 11y ago
  Supposedly you see the same drop in crime after lead was phased out of gasoline: http://www.motherjones.com/environment/2016/02/lead-exposure-gasoline-crime-increase-children-health http://www.motherjones.com/environment/2016/02/lead-exposure... > That tip took Nevin in a different direction. The biggest source of lead in the postwar era, it turns out, wasn't paint. It was leaded gasoline. And if you chart the rise and fall of atmospheric lead caused by the rise and fall of leaded gasoline consumption, you get a pretty simple upside-down U: Lead emissions from tailpipes rose steadily from the early '40s through the early '70s, nearly quadrupling over that period. Then, as unleaded gasoline began to replace leaded gasoline, emissions plummeted. > Intriguingly, violent crime rates followed the same upside-down U pattern. The only thing different was the time period: Crime rates rose dramatically in the '60s through the '80s, and then began dropping steadily starting in the early '90s. The two curves looked eerily identical, but were offset by about 20 years. > So Nevin dove in further, digging up detailed data on lead emissions and crime rates to see if the similarity of the curves was as good as it seemed. It turned out to be even better: In a 2000 paper (PDF) he concluded that if you add a lag time of 23 years, lead emissions from automobiles explain 90 percent of the variation in violent crime in America. Toddlers who ingested high levels of lead in the '40s and '50s really were more likely to become violent criminals in the '60s, '70s, and '80s. > And with that we have our molecule: tetraethyl lead, the gasoline additive invented by General Motors in the 1920s to prevent knocking and pinging in high-performance engines. As auto sales boomed after World War II, and drivers in powerful new cars increasingly asked service station attendants to "fill 'er up with ethyl," they were unwittingly creating a crime wave two decades later.
  - Shivetya 11y ago
    Well he was certainly after a result he wanted, lead was phased out of house paints starting after 1971 and gone by 1978, meaning anything built before 78 was suspect. This may still be a problem in some older housing especially in cities. Leaded gasoline didn't fully phase out until the 80s and was still for sale in places until 91. Even in Canada leaded gasoline wasn't banned until 1990. So while it definitely had a large influence we have to realize lead was everywhere, it was cheap, it had so many wonderful uses, but it most certainly didn't vanish in the seventies.
qaq 11y ago
Yes it's so easy to isolate all other possible factors, and correlation is obviously a definitive proof of causation.
- dredmorbius 11y ago
  There is a causal relation between lead and brain development, with strong relations between brain development and causal activity. This is yet another corralative relation between introduction of leaded plumbing and long-term behavioral impacts. False premise on your part.
  - qaq 11y ago
    Yes obviously prohibition and organized crime are minor factors in homicide rates very convenient time period chosen. In larger urban areas using more lead pipes is obviously a dominating factor and obviously not being a major black markets in prohibition era and thus center for organized crime.
    - dredmorbius 11y ago
      You know, if you'd conceed points and then raise other considerations your arguments might be taken as in good faith. As it is, I find it hard to extend that courtesy. You might want to consider this in future. As the points you raise have merits, but not in the context and tone in which your make them.
      - qaq 11y ago
        You are right but having stats background it get's tiresome looking at how people are abusing the craft. There is obviously little harm from a "study" like this, but this sad state of things affects much more critical areas like medical field. You see so much of misuse and misapplication makes you angry after a while.
        Hondor 11y ago
ves 11y ago
How is this even remotely good science? So far as I can tell, they didn't admit the possibility that this can be either complete noise (if you have, say 100 diseases, and you're looking for time-series correlations, or performing tests with too low an alpha or power) or caused by a confounder. The task of making causal claims is a difficult one, and not one to be made lightly. The literature is replete with examples of this going terribly wrong, even with perceived physical justifications. See [0]: tylervigen.com [1]: http://nerdsonwallstreet.typepad.com/my_weblog/files/dataminejune_2000.pdf http://nerdsonwallstreet.typepad.com/my_weblog/files/datamin... [2]: http://www.huffingtonpost.com/2013/04/16/reinhart-rogoff-austerity-research-errors_n_3094015.html http://www.huffingtonpost.com/2013/04/16/reinhart-rogoff-aus... [3]: http://www.economist.com/node/5246700 http://www.economist.com/node/5246700
- josu 11y ago
  The article is bad (MotherJones), the paper may be better [1]. I've only skimmed it, but it looks at the correlation between distance from a lead factory and homicide rate, which probably increases the signal/noise ratio. [1] http://scholar.harvard.edu/files/jfeigenbaum/files/feigenbaum_muller_lead_crime.pdf http://scholar.harvard.edu/files/jfeigenbaum/files/feigenbau...
  - ves 11y ago
    Do you not admit the confounder that proximity to a lead factory should also correlate with socioeconomic status? I don't have time to check out the article this week, but will soon.
    - maxerickson 11y ago
      They use rail distance to lead refineries as an instrument variable. They briefly discuss direct poisoning from a refinery. The real kicker is that lead pipes combined with acidic water have a higher effect than lead pipes combined with basic water.
    - peejaybee 11y ago
      "Third, a city-level analysis such as ours does not suffer from a common problem with individual-level studies, namely that individuals exposed to lead typically come from poor neighborhoods with both low-quality housing and high crime rates. Common confounders of the lead-crime relationship in individual-level studies pose less of a problem in our city-level study, where in most cases the entire city population was exposed to lead through water." Paper's here: http://scholar.harvard.edu/files/jfeigenbaum/files/feigenbaum_muller_lead_crime.pdf http://scholar.harvard.edu/files/jfeigenbaum/files/feigenbau...
jamesash 11y ago
Around 1900, the "tin" in tin cans contained about 12% lead, which leached into fruits and vegetables. You have to wonder if there's any way of correcting for that. [Source: "The Great A&P" by Marc Levinson, page 50.][Edit: read the paper cited and they make no mention of this]
- blatherard 11y ago
  Do you suspect that lead to be distributed in a way that would confound the results? In the absence of a theory, I'd expect lead to be fairly evenly distributed amongst cities in that particular way.
  - lostlogin 11y ago
    I read the parent as pondering whether it would be possible to compare populations that have had leaded canned food to those that haven't.
tacos 11y ago
I get all my science from motherjones.com! From fluoride to sugar to weed, this is where Pulitzer meets Nobel. Seriously though: a motherjones.com post of this quality as #1 on HN is a new low. I miss the days of pg obsessively micromanaging everything 'round these parts.
- yarou 11y ago
  If memory serves, pg was actually pretty hands off - unless a submission was politically controversial, most topics were allowed. I haven't really noticed anything different, other than dang commenting more publicly on moderation decisions.
  - tacos 11y ago
    pg was downright addicted and glued to this site, and pulled levers at all hours.
- 5ilv3r 11y ago
  Yeah, this is crap reporting. The author has no idea what he is even linking to.
curtis 11y ago
The blog post links to this paper: Lead Exposure and Violent Crime in the Early Twentieth Century -- http://scholar.harvard.edu/files/jfeigenbaum/files/feigenbaum_muller_lead_crime.pdf http://scholar.harvard.edu/files/jfeigenbaum/files/feigenbau...
- deleted 11y ago
  [deleted]
deleted 11y ago
[deleted]
dzink 11y ago
Mentioned this to a doctor in the family and their instant reply back was "Lead poisoning medically results in lower IQ". Then found some info about it here: http://www.environmentalhealthnews.org/ehs/newscience/iq-effects-childhood-lead-exposure-persist-in-adults/ http://www.environmentalhealthnews.org/ehs/newscience/iq-eff...
- lostlogin 11y ago
  Should have asked him/her what the medical IQ scale looks like. I'd guess it's the same but more expensive.
5ilv3r 11y ago
The author used the wrong chart and had to correct it?? Get this trash off the front page.
- lostlogin 11y ago
  Did you notice this or just read the authors correction and notification of their mistake? How do you handle your errors? Or do you not make any?
bpchaps 11y ago
Lead poisoning is especially strange. I'm convinced that I have it, in contrast to the bipolar diagnosis I've been given. I used to do competitive shooting where I'd practice five days out of the week and compete on average of maybe once each weekend. The projectiles we shot were entirely lead, there was never any push for cleaning our hands, and the lead trap was never, ever cleaned (lead dust yay). Problem is, every time I describe the problem and the reasoning behind it, no doctor takes me seriously to the point of laughing sometimes. It's ridiculous that lead's been researched so much, yet no doctor I've talked to understands it enough to even humor the idea. Not trying to self diagnose, but a little bit of "Hmm... yeah, maybe", would be nice. I've also reached out to researchers in the field. The modern ones who've done extensive research have all moved to different fields and aren't willing to help out. Really frustrating. If anybody has any sources for help, I'd love it.
- colanderman 11y ago
  Have you considered a blood test? [1] You could probably get a referral for generic blood work easily (claim you're concerned about vitamin levels or something), and then ask the testing agency to check for lead levels. [1] https://en.wikipedia.org/wiki/Lead_poisoning#Diagnosis https://en.wikipedia.org/wiki/Lead_poisoning#Diagnosis
  - bpchaps 11y ago
    Blood tests are useless after a certain point, as far as I know. The tests for neurological effects are a bit more complicated and require bone biopsies. Been a while since I've looked into it, so I might be wrong.
    - irremediable 11y ago
      Just from quickly skimming the literature, it looks like you can measure it in vivo with X-ray fluorescence. Getting access to one of those would be hard, but you might be able to persuade a researcher to use you in a trial? I imagine you've already looked into this a fair bit. Are you on medication to help with the (diagnosed) bipolar disorder? Do you find that e.g. lithium eases your symptoms? If so, I'd be inclined to think you're bipolar -- irrespective of whether you also have low-level lead poisoning.
brownbat 11y ago
Crime trends are hard, and every theory we have seems to have its own set of weird statistical quirks. That "we don't know much" nuance rarely makes it into short articles. The closest I've seen is in the Atlantic, where they basically have a whole series devoted to problems with no easy answers. http://www.theatlantic.com/politics/archive/2016/04/what-caused-the-crime-decline/477408/ http://www.theatlantic.com/politics/archive/2016/04/what-cau... Maybe the lead theory is right, but these are tough issues that are well studied, full of methodological hazards, so it's worth being extremely cautious when interpreting results about anything that drives crime trends.
- deleted 11y ago
  [deleted]
- Steko 11y ago
  > That "we don't know much" nuance rarely makes it into short articles. Well it made it into this one: Click on my post from last year to get more details about both the strengths and weaknesses of this paper. As with any retrospective study like this, there are reasons to be cautious about the results. Clicking the link gives us a pretty nuanced discussion: On the negative side, it's risky to look solely at homicide numbers. This is because the absolute number of murders is small, especially on a city-by-city basis, and that means there's a lot of noise in the numbers. This is especially true when you're limited to a period of time as short as 15 years. There's also the fact that this was an era when lead paint was widely used, and that's very hard to tease out from the use of lead in pipes. Finally, there's the usual problem of any study like this: what do you control for? The use of lead pipes is plausibly unrelated to anything else related to crime, but it's impossible to know for sure. The authors do control for black population, foreign-born population, occupations, home ownership, and gender breakdown, and that reduces their effect size from 11.4 percent to 8.6 percent. Might some other control reduce it even further? Plus there's the anomaly of Southern cities. Very few of them used lead pipes, but some did, and their murder rates were essentially no different from any other Southern cities. Why? It's possible that this is because their use of lead pipes was small (F&M have data on lead pipe use by city, but not on how much lead piping was used in each city). But it's still odd.
deleted 11y ago
[deleted]
rdancer 11y ago
I wonder what else may have been happening circa 1814–1818 that could make people more violent in its aftermath?
madengr 11y ago
The media refuses to say where the Flint, MI lead is coming from. It's coming from lead pipes in private residences, since the minerals in the water have changed.
askyourmother 11y ago
Well the lead removal has reduced crime, but the plastic replacement pipes and the hormone disrupting chemicals contained within are certainly having a great effect! Wonder if they will start to chart that?

147 points by curtis 11y ago

astrodust 11y ago

No doubt we'll find an unfortunate blip in twenty years in Flint.

bluedino 11y ago
Speaking of Flint (and Chicago as well), why are murders/shootings at new highs when they went down in the 90's like in every other area? Did they starting using lead paint again in the 80's?
- sudojudo 11y ago
  Pretty sure the up-tick has more to do with socioeconomics and the drug war than anything else. I don't have any sources at hand, so take this with a grain of salt. But, I've often seen it argued that Reagan era drug policies were detrimental to poor minorities, especially black men. The problems we see today are the trickle-down effects (couldn't resist) of turning an entire generation of fathers into disenfranchised criminals.
  - trhway 11y ago
    yes, one can google a lot on crack cocaine and its correlation with crime back then and later.
  - astrodust 11y ago
    Throwing a generation of fathers in jail for trivial offenses not only erodes confidence in the judicial system, it leaves children without a role model. Like if dad's in jail, who cares if you end up there eventually. Prison isn't a deterrent any more. In some communities doing time is just part of growing up.

ori_b 11y ago

> Cities that used iron pipes, in contrast, had higher rates of death from circulatory disease, cancer, and cerebral hemorrhage. We know of no scientific literature to motivate these latter relationships. Is it possible that this is just because people weren't dying of other things first?

toomuchtodo 11y ago
Supposedly you see the same drop in crime after lead was phased out of gasoline: http://www.motherjones.com/environment/2016/02/lead-exposure-gasoline-crime-increase-children-health http://www.motherjones.com/environment/2016/02/lead-exposure... > That tip took Nevin in a different direction. The biggest source of lead in the postwar era, it turns out, wasn't paint. It was leaded gasoline. And if you chart the rise and fall of atmospheric lead caused by the rise and fall of leaded gasoline consumption, you get a pretty simple upside-down U: Lead emissions from tailpipes rose steadily from the early '40s through the early '70s, nearly quadrupling over that period. Then, as unleaded gasoline began to replace leaded gasoline, emissions plummeted. > Intriguingly, violent crime rates followed the same upside-down U pattern. The only thing different was the time period: Crime rates rose dramatically in the '60s through the '80s, and then began dropping steadily starting in the early '90s. The two curves looked eerily identical, but were offset by about 20 years. > So Nevin dove in further, digging up detailed data on lead emissions and crime rates to see if the similarity of the curves was as good as it seemed. It turned out to be even better: In a 2000 paper (PDF) he concluded that if you add a lag time of 23 years, lead emissions from automobiles explain 90 percent of the variation in violent crime in America. Toddlers who ingested high levels of lead in the '40s and '50s really were more likely to become violent criminals in the '60s, '70s, and '80s. > And with that we have our molecule: tetraethyl lead, the gasoline additive invented by General Motors in the 1920s to prevent knocking and pinging in high-performance engines. As auto sales boomed after World War II, and drivers in powerful new cars increasingly asked service station attendants to "fill 'er up with ethyl," they were unwittingly creating a crime wave two decades later.
- Shivetya 11y ago
  Well he was certainly after a result he wanted, lead was phased out of house paints starting after 1971 and gone by 1978, meaning anything built before 78 was suspect. This may still be a problem in some older housing especially in cities. Leaded gasoline didn't fully phase out until the 80s and was still for sale in places until 91. Even in Canada leaded gasoline wasn't banned until 1990. So while it definitely had a large influence we have to realize lead was everywhere, it was cheap, it had so many wonderful uses, but it most certainly didn't vanish in the seventies.

qaq 11y ago

Yes it's so easy to isolate all other possible factors, and correlation is obviously a definitive proof of causation.

dredmorbius 11y ago
There is a causal relation between lead and brain development, with strong relations between brain development and causal activity. This is yet another corralative relation between introduction of leaded plumbing and long-term behavioral impacts. False premise on your part.
- qaq 11y ago
  Yes obviously prohibition and organized crime are minor factors in homicide rates very convenient time period chosen. In larger urban areas using more lead pipes is obviously a dominating factor and obviously not being a major black markets in prohibition era and thus center for organized crime.
  - dredmorbius 11y ago
    You know, if you'd conceed points and then raise other considerations your arguments might be taken as in good faith. As it is, I find it hard to extend that courtesy. You might want to consider this in future. As the points you raise have merits, but not in the context and tone in which your make them.
    - qaq 11y ago
      You are right but having stats background it get's tiresome looking at how people are abusing the craft. There is obviously little harm from a "study" like this, but this sad state of things affects much more critical areas like medical field. You see so much of misuse and misapplication makes you angry after a while.
      - Hondor 11y ago

ves 11y ago

How is this even remotely good science? So far as I can tell, they didn't admit the possibility that this can be either complete noise (if you have, say 100 diseases, and you're looking for time-series correlations, or performing tests with too low an alpha or power) or caused by a confounder. The task of making causal claims is a difficult one, and not one to be made lightly. The literature is replete with examples of this going terribly wrong, even with perceived physical justifications. See [0]: tylervigen.com [1]: http://nerdsonwallstreet.typepad.com/my_weblog/files/dataminejune_2000.pdf http://nerdsonwallstreet.typepad.com/my_weblog/files/datamin... [2]: http://www.huffingtonpost.com/2013/04/16/reinhart-rogoff-austerity-research-errors_n_3094015.html http://www.huffingtonpost.com/2013/04/16/reinhart-rogoff-aus... [3]: http://www.economist.com/node/5246700 http://www.economist.com/node/5246700

josu 11y ago
The article is bad (MotherJones), the paper may be better [1]. I've only skimmed it, but it looks at the correlation between distance from a lead factory and homicide rate, which probably increases the signal/noise ratio. [1] http://scholar.harvard.edu/files/jfeigenbaum/files/feigenbaum_muller_lead_crime.pdf http://scholar.harvard.edu/files/jfeigenbaum/files/feigenbau...
- ves 11y ago
  Do you not admit the confounder that proximity to a lead factory should also correlate with socioeconomic status? I don't have time to check out the article this week, but will soon.
  - maxerickson 11y ago
    They use rail distance to lead refineries as an instrument variable. They briefly discuss direct poisoning from a refinery. The real kicker is that lead pipes combined with acidic water have a higher effect than lead pipes combined with basic water.
  - peejaybee 11y ago
    "Third, a city-level analysis such as ours does not suffer from a common problem with individual-level studies, namely that individuals exposed to lead typically come from poor neighborhoods with both low-quality housing and high crime rates. Common confounders of the lead-crime relationship in individual-level studies pose less of a problem in our city-level study, where in most cases the entire city population was exposed to lead through water." Paper's here: http://scholar.harvard.edu/files/jfeigenbaum/files/feigenbaum_muller_lead_crime.pdf http://scholar.harvard.edu/files/jfeigenbaum/files/feigenbau...

jamesash 11y ago

Around 1900, the "tin" in tin cans contained about 12% lead, which leached into fruits and vegetables. You have to wonder if there's any way of correcting for that. [Source: "The Great A&P" by Marc Levinson, page 50.][Edit: read the paper cited and they make no mention of this]

blatherard 11y ago
Do you suspect that lead to be distributed in a way that would confound the results? In the absence of a theory, I'd expect lead to be fairly evenly distributed amongst cities in that particular way.
- lostlogin 11y ago
  I read the parent as pondering whether it would be possible to compare populations that have had leaded canned food to those that haven't.

tacos 11y ago

I get all my science from motherjones.com! From fluoride to sugar to weed, this is where Pulitzer meets Nobel. Seriously though: a motherjones.com post of this quality as #1 on HN is a new low. I miss the days of pg obsessively micromanaging everything 'round these parts.

yarou 11y ago
If memory serves, pg was actually pretty hands off - unless a submission was politically controversial, most topics were allowed. I haven't really noticed anything different, other than dang commenting more publicly on moderation decisions.
- tacos 11y ago
  pg was downright addicted and glued to this site, and pulled levers at all hours.
5ilv3r 11y ago
Yeah, this is crap reporting. The author has no idea what he is even linking to.

curtis 11y ago

The blog post links to this paper: Lead Exposure and Violent Crime in the Early Twentieth Century -- http://scholar.harvard.edu/files/jfeigenbaum/files/feigenbaum_muller_lead_crime.pdf http://scholar.harvard.edu/files/jfeigenbaum/files/feigenbau...

deleted 11y ago
[deleted]

deleted 11y ago

[deleted]

dzink 11y ago

Mentioned this to a doctor in the family and their instant reply back was "Lead poisoning medically results in lower IQ". Then found some info about it here: http://www.environmentalhealthnews.org/ehs/newscience/iq-effects-childhood-lead-exposure-persist-in-adults/ http://www.environmentalhealthnews.org/ehs/newscience/iq-eff...

lostlogin 11y ago
Should have asked him/her what the medical IQ scale looks like. I'd guess it's the same but more expensive.

5ilv3r 11y ago

The author used the wrong chart and had to correct it?? Get this trash off the front page.

lostlogin 11y ago
Did you notice this or just read the authors correction and notification of their mistake? How do you handle your errors? Or do you not make any?

bpchaps 11y ago

Lead poisoning is especially strange. I'm convinced that I have it, in contrast to the bipolar diagnosis I've been given. I used to do competitive shooting where I'd practice five days out of the week and compete on average of maybe once each weekend. The projectiles we shot were entirely lead, there was never any push for cleaning our hands, and the lead trap was never, ever cleaned (lead dust yay). Problem is, every time I describe the problem and the reasoning behind it, no doctor takes me seriously to the point of laughing sometimes. It's ridiculous that lead's been researched so much, yet no doctor I've talked to understands it enough to even humor the idea. Not trying to self diagnose, but a little bit of "Hmm... yeah, maybe", would be nice. I've also reached out to researchers in the field. The modern ones who've done extensive research have all moved to different fields and aren't willing to help out. Really frustrating. If anybody has any sources for help, I'd love it.

colanderman 11y ago
Have you considered a blood test? [1] You could probably get a referral for generic blood work easily (claim you're concerned about vitamin levels or something), and then ask the testing agency to check for lead levels. [1] https://en.wikipedia.org/wiki/Lead_poisoning#Diagnosis https://en.wikipedia.org/wiki/Lead_poisoning#Diagnosis
- bpchaps 11y ago
  Blood tests are useless after a certain point, as far as I know. The tests for neurological effects are a bit more complicated and require bone biopsies. Been a while since I've looked into it, so I might be wrong.
  - irremediable 11y ago
    Just from quickly skimming the literature, it looks like you can measure it in vivo with X-ray fluorescence. Getting access to one of those would be hard, but you might be able to persuade a researcher to use you in a trial? I imagine you've already looked into this a fair bit. Are you on medication to help with the (diagnosed) bipolar disorder? Do you find that e.g. lithium eases your symptoms? If so, I'd be inclined to think you're bipolar -- irrespective of whether you also have low-level lead poisoning.

brownbat 11y ago

Crime trends are hard, and every theory we have seems to have its own set of weird statistical quirks. That "we don't know much" nuance rarely makes it into short articles. The closest I've seen is in the Atlantic, where they basically have a whole series devoted to problems with no easy answers. http://www.theatlantic.com/politics/archive/2016/04/what-caused-the-crime-decline/477408/ http://www.theatlantic.com/politics/archive/2016/04/what-cau... Maybe the lead theory is right, but these are tough issues that are well studied, full of methodological hazards, so it's worth being extremely cautious when interpreting results about anything that drives crime trends.

deleted 11y ago
[deleted]
Steko 11y ago
> That "we don't know much" nuance rarely makes it into short articles. Well it made it into this one: Click on my post from last year to get more details about both the strengths and weaknesses of this paper. As with any retrospective study like this, there are reasons to be cautious about the results. Clicking the link gives us a pretty nuanced discussion: On the negative side, it's risky to look solely at homicide numbers. This is because the absolute number of murders is small, especially on a city-by-city basis, and that means there's a lot of noise in the numbers. This is especially true when you're limited to a period of time as short as 15 years. There's also the fact that this was an era when lead paint was widely used, and that's very hard to tease out from the use of lead in pipes. Finally, there's the usual problem of any study like this: what do you control for? The use of lead pipes is plausibly unrelated to anything else related to crime, but it's impossible to know for sure. The authors do control for black population, foreign-born population, occupations, home ownership, and gender breakdown, and that reduces their effect size from 11.4 percent to 8.6 percent. Might some other control reduce it even further? Plus there's the anomaly of Southern cities. Very few of them used lead pipes, but some did, and their murder rates were essentially no different from any other Southern cities. Why? It's possible that this is because their use of lead pipes was small (F&M have data on lead pipe use by city, but not on how much lead piping was used in each city). But it's still odd.

deleted 11y ago

[deleted]

rdancer 11y ago

I wonder what else may have been happening circa 1814–1818 that could make people more violent in its aftermath?

madengr 11y ago

The media refuses to say where the Flint, MI lead is coming from. It's coming from lead pipes in private residences, since the minerals in the water have changed.

askyourmother 11y ago

Well the lead removal has reduced crime, but the plastic replacement pipes and the hormone disrupting chemicals contained within are certainly having a great effect! Wonder if they will start to chart that?