When I was in college, one of my professors used to complain that too many of his students had no “number gut.”
A number gut is an intuitive feel for the possible magnitude of a particular number that describes a particular phenomenon. A good number gut tells you if the results of some calculation are at least in the ball park. People develop number guts through experience with particular phenomena but they also develop it just by doing a lot math by hand. When you do math by hand, you have to do more physical writing to deal with very large numbers so you develop a kind of visceral sense of scale. The coming of calculators, however, destroyed this physical relationship, leading many budding scientists to make gross errors of magnitude without realizing it.
The lack of a number gut destroys any sense of context for numbers that describe a phenomenon, leading people to casually accept as valid statements that a little double-checking would show to be just plain silly.
For example, there was news story published back in the late 80s that reported that the state of New Jersey produced 50 billion used tires every year which caused a huge environmental problem. The story got widely disseminated before somebody pointed out that since New Jersey had a population on only around 8 million, 50 billion tires a year came out to 6,250 tires per capita per year. The story got play because the editors had no intuitive feel for the significance of 4 orders of magnitude difference between the size of the population and the tire consumption.
Which brings me to the subject of the Lancet Iraqi Mortality Survey (LIMS) [free reg].
A lot of people who would know better in another context seem perfectly willing to swallow the estimate of 300,000+ dead that LIMS reports with the Falluja cluster included. Examined in detail, LIMS reports that of those 300,000, roughly 250,000 died from violence, and of those something like 220,000 died from Coalition airstrikes. The LIMS authors even suggest [p6 pg7] that this is likely an underestimate.
Anyone with a good number gut for such phenomenon would immediately recognize such numbers as implausible.
Why couldn’t 250,000 be dead from violence? Well, the first clue is that the total population of Iraq is around 25 million, so 250,000 dead represents 1% of the entire population. That means if LIMS is accurate then 1 in every 100 Iraqis were killed in the war up to Sept 2004. So what? After all, it’s a war and lots of people die in wars right? Well, not as many as most people think.
For example, during WWII the Japanese mainland suffered the most extensive aerial bombardment in history. Every major urban area save one (Kyoto) was burned to the ground. On march 10th, 1945 the great Tokyo fire raid burned down a third of the city and killed 100,000 people. Two major cities were nuked. Japan at the time had a population of 78 million, so 1% of the population would have been around 780,000. Now, what is your guess as to the number of Japanese killed on the Japanese mainland?
Did you guess around 500,000? Under 1%? Well, that is in fact the number (note: that’s only dead, not dead-and-wounded).
So, with the Falluja cluster included, LIMS asks us to believe that Iraq has suffered a worse proportional aerial bombardment than did Japan during WWII. Common sense compels us to ask: does Iraq look like it suffered such a fate? Where are the mass graves? Where are the leveled cities? Where are the hundreds of thousands of walking wounded? Where are the millions of refugees that such intense fighting must have inevitably produced?
Worse still, given the known geographical areas where the fighting occurred, most of the deaths would have had to be concentrated in an area of 100 klicks or so from Baghdad, which would have meant an even higher percentage of the local population killed and the physical evidence even more obvious. (After the recent publication of the ILCS, it also means that the deaths would have to been compressed in time as well. The ILCS reported only 24,000 war related deaths up until May 25, 2004. For the LIMS to be true, the additional 200,000 deaths would have to have occurred between then and early Sept 2004 when LIMS was conducted. That comes out to roughly 2,000 deaths per day.)
Even the most casual student of military history or, indeed, just a curious person with access to Google, should instantly know that the 250,000 figure would be far too high based on the direct observation of facts on the ground. You can’t kill that many people without leaving massive physical evidence. There is absolutely no precedent for killing that high a percentage of the population with air power (or even ground forces) but leaving so few clues that the information could only be teased out by an epidemiological study.
People are doing the same thing with LIMS that they did with New Jersey tire story. They hear a number from an authority figure and then accept it without thinking about its real-world implications. Had similar results been offered in a less political context they would have been rejected immediately. People’s number gut or even just their basic BS detectors would have gone off when they heard the 300,000 number. That in turn would have led the more experienced to question the basic methodology of the study. Everyone should have wondered whether it was good practice to use the experiences of one little neighborhood of 30 houses as representative of the wider experience of everyone in Iraq or even of just one governorate. At the very least, it should have caused the complete removal of the data from the cluster that produced the nonsensical results.
That so many swallow such implausible numbers without any other supporting evidence (and indeed actively ignore opposing evidence) indicates how desperately they want the liberation of Iraq to be judged a failure. They are willing to corrupt our scientific institutions, and to provide powerful propaganda for the fascists, in their selfish pursuit of their own narrow political goals.