QotD: Where factoids come from

Decades ago, in the days when I labo(u)red in the Central Laboratory at the bottle factory, one of my collegues was dispatched to a conference on air pollution. Upon his return, he related the contents of a paper there presented.

I don't remember the details, but recall the main thrust of it.

In those days, there were numerous claims that "air pollution costs every man, woman, and child in the United States $137.63 every year" or some such number. The paper in question addressed the source of that widely published figure.

It developed that around 1890, a Pittsburgh (The Smokey City) newspaper had printed an article which reported the cost of cleaning the exterior of each of several office buildings during the previous year.

A a year or so later, someone else totaled those figures, divided by the number of buildings reported, multiplied by the number of office buildings in the Golden Triangle and reported "Air Pollution Cost to Pittsburg Businesses".

Still later, someone took that figure, divided by the population of Pittsburgh, multiplied by the population of the Allegheny County, and published "Cost of Air Pollution for Allegheny County in 1910".

Later, someone divided that by the number of steel mills in Allegheny County, multiplied by the number of steel mills in the state and called the result "Pennsylvania's Cost of Air Pollution".

Later, someone multiplied that figure by the number of states east of the Mississippi to arrive at "Cost to Eastern United States Due to Air Pollution".

Along around 1925, someone adjusted the figure to account for inflation.

In the 1930's someone divided the 1925 figure by the population of the states east of the Mississippi to arrive at an "every man, woman, and child cost of air pollution".

Someone else compared the unadjusted pre-1925 figure to the adjusted 1925 figure, divided the difference by the population of the eastern states to obtain "Increase per capita in Cost of Air Pollution in a Single Year".

Just after WW2 (the big one), the 1930's "every man, etc.." figure was adjusted for inflation, multiplied by the population of the United States, divided by the number of states, and published as "Cost of Air Pollution to Each State".

Finally, after a few more such manipulations over the years, the then- current cost of $137.63 was published.

As noted in the beginning, that's not exactly what the paper said, but the general idea is there. Along the way it was noted that, for example, an alleged total cost for Pittsburgh in 1900 had been divided by the 1914 population of Pittsburgh to get a cost per capita, then multiplied by the 1920 population of Pennsylvania to get a total for the state, even though the population numbers changed from year to year.

The paper's conclusions were:

1) There is a cost incurred by air pollution.

2) No one knows what that cost is.

3) If it is $137.62 per capita, that's just good luck.

4) That the quoted "Cost of Air Pollution . . ." should be scrapped at once.

Robert Netzlof, posting to Yahoo Group "Railroad_Modeling_Still_Makes_Me_Grumpy", 2007-11-21