Lead and crime, continued

Lead causes crime. How much of the great crime wave and the great crime decline were lead-driven is unclear.

Yesterday I returned to banging the (Kevin) drum about the pernicious effects of environmental lead. Both a note from a reader and comments elsewhere about Kevin’s latest post suggest that an earlier post of mine had created confusion.

Here’s the note:

Mark, in your latest post, you seem to be believing the lead hypothesis for violent crime again. But here I thought you said that Phil Cook changed your mind. Are there new data that tipped you back, or is there a hole in Cook’s argument?

There are two different claims here:

  1. Lead causes crime, and the effect size is large.
  2. Decreasing lead exposure was the primary cause of the crime decline that started in 1994.

#1 is certainly true, and nothing Cook has written or said contradicts it. We have both statistical evidence at the individual level and a biological understanding of the brain functions disrupted by lead.

Cook convinced me that #2 is not true, or at least is not the whole story, because the decline happened in all cohorts while lead exposure deceased only for the younger cohorts. You can still tell plausible stories about how the young’uns drove the homicide wave of the late 1980s/early 1990s and that less violent subsequent cohorts of young’uns reduced the overall level of violence, but that’s not as simple a story. In a world of many interlinked causes and both positive and negative feedbacks, the statement “X% of the change in A was caused by a change in B” has no straightforward empirical sense.

So I’m absolutely convinced that lead is criminogenic, in addition to doing all sorts of other personal and social harm, and strongly suspect that further reductions in lead exposure (concentrating on lead in interior paint and lead in soil where children play) would yield benefits in excess of their costs, even though those costs might be in the billions of dollars per year. What’s less clear is how much of the crime increase starting in the early 1960s and the crime decrease starting in the early 1990s (and the rises and falls of crime in the rest of the developed world) should be attributed to changes in lead exposure.

The original point of yesterday’s post stands: When you hear people complaining about environmental regulation, what they’re demanding is that businesses should be allowed to poison children and other living things. No matter how often they’re wrong about that – lead, pesticides, smog, sulphur oxides, chlorofluorocarbons, estrongenic chemicals – they keep on pretending that the next identified environmental problem – global warming, for example – is just a made-up issue, and that dealing with it will tank the economy. Of course health and safety regulation can be, and is, taken to excess. But the balance-of-harms calculation isn’t really hard to do. And the demand for “corporate free speech” is simply a way of giving the perpetrators of environmental crimes a nearly invincible political advantage over the victims.

Author: Mark Kleiman

Professor of Public Policy at the NYU Marron Institute for Urban Management and editor of the Journal of Drug Policy Analysis. Teaches about the methods of policy analysis about drug abuse control and crime control policy, working out the implications of two principles: that swift and certain sanctions don't have to be severe to be effective, and that well-designed threats usually don't have to be carried out. Books: Drugs and Drug Policy: What Everyone Needs to Know (with Jonathan Caulkins and Angela Hawken) When Brute Force Fails: How to Have Less Crime and Less Punishment (Princeton, 2009; named one of the "books of the year" by The Economist Against Excess: Drug Policy for Results (Basic, 1993) Marijuana: Costs of Abuse, Costs of Control (Greenwood, 1989) UCLA Homepage Curriculum Vitae Contact: Markarkleiman-at-gmail.com

4 thoughts on “Lead and crime, continued”

  1. It strikes me that the use of the word "cost" here reflect just how deeply we have swallowed free market dogma. If it means anything, it means that society loses money as a result. But who loses money? Not the workers who remove the lead. Not the children that grow up to be more creative and not in jail. I think the background meaning is that it lowers future GDP, but that is only true if the money spent on remediation would have been better spent on something else. The totally unproven assumption behind that idea is that government directed spending, by definition, contributes less to GDP than non-government directed spending. Of course the obvious consequence of that would be that China has a negative GDP. But that's not true, is it?

    1. Yes. Abstractly, social welfare is the net surplus between the set of disutilities – unpleasant work, pain and illness, medical treatments, incarceration, ugly environments, interpersonal conflict – and utilities: sensory and social pleasures and satisfactions. GDP includes contributors to both. The extreme case is guns: they raise US GDP compared to Europe or Japan by gun sales, ER treatments, funerals, criminal justice and incarceration. They lower welfare on any sane accounting.

  2. How are things looking worldwide, vis-a-vis lead exposure? Lowering exposure does seem like a no-brainer way forward.

  3. In the immortal words of Saint Ronald of Reagan, "Well, Mark, there you go again."

    Real men simply stand by what they said. Only liberals explain what they said. Real men know that "the business of the country is business." Only liberals think life is complex, with conflicting priorities.

    You are obviously some kind of liberal.

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