Wednesday, January 09, 2013

Lead In Your Pencil.

The theory that the fall in crime over the last generation has been due to the phasing out of lead additives in petrol has received another airing recently.

The last time I mentioned the idea on this blog it was to ridicule the idea, but over the last few years it seems to have stood up fairly well- to the point where it is perhaps the biggest underlying global cause of long term fluctuations in crime trends. (When I'm admitting I was partly wrong I tend to waffle).

However there is a danger of neglecting cultural and policy impacts on crime levels in affecting crime levels even if they aren't the only factors. For example there has been a major difference in the homicide rate of the northern and souther United States going back to before the country was actually formed- and long predating the use of lead in petrol. Even today the much vaunted fall in crime experienced by New York cannot really be explained by lead alone, because the rate in New York fell in relative terms compared to other cities (to the point where the much small city of Chicago has more murders in total than New York). So there still is a significant role for effective policing and sentencing in cutting crime.

If the theory continues to hold water then it is a significant victory for environmentalists- at least the saner ones- because it seems that pollution caused side effects far more severe than could have been predicted based upon the best evidence available at the time. The precautionary principle has in this case at least been vindicated.


James Higham said...

Phew - after that, Ross, I'm more confused than ever.

A K Haart said...

I used to worry about environmental lead. These issues didn't usually bother me, but a few decades ago we were finding such high levels in soils and especially sewage because of road runoff.

It was a relief when lead in petrol was phased out - one of the best environmental moves we ever made in my view.

banned said...

I remember being told as a small child that nibbling on the (lead-based) paint at school and home would make me mental (this in the 1960's) so it's not a new idea. I recently watched a documentary on the roman empire which suggested that one reason for their fall was that their eating and drinking vessels were usually made of lead which might have turned them mentalver the decades.

The expression 'mad as a hatter' has been around for generations and refers to what happened to the straw boater makers of Luton who used mercury in their work.

banned said...

"mentalver" = mental over :)

SadButMadLad said...

Lead is not likely to have been a major factor in causes of crime.

Many countries (Eg. Russia) used lead and didn't have the same drop or increase in crime matching that of their use of lead additives (or pipes).

The UK used a lot of lead pipes in the Victorian times. Were they a hot bed of crime? Nope. And the Romans attitudes cannot be compared to modern ones and said to be barbaric. Their attitudes were just due to the time period they lived in, just like the barbaric Vikings who didn't have as much contact with lead.

What is true is that lead poisoning can make you mad and mentally deficient, but that doesn't necessarily lead to crime.

Ross said...

Banned-the effects are well known, but it seems that what was underestimated was the doses at which the effects took hold.