Color Me Skeptical

The article is interesting, but color me skeptical.

Extrapolating from a set of 300 rural dam sites is a bit like looking through a keyhole to describe both the house and the garden.

That said, population estimates are *always* wrong.

A short story…

Back in 1986, I was the organizer of a session on census adjustment at the annual conference of the American Association of Science. The topic of the panel had to do with census reapportionment for congressional seats. If the courts decided to exclude illegal immigrants from the count, how could that be done? How did we count permanent resident green card holders? Did we count them at all? And what about the millions of young black men who, for whatever reason, were always missing in census counts? Was a deep sample survey actually more accurate than a nose-by-nose count?

All good questions, but before we got too far into the thicket, I wanted to prick a few balloons.

I began the panel by noting that in 1980 the U.S. Census Bureau had counted exactly 226,545,805 people, but that the margin of error that the Census Bureau freely admitted to was 2.5 percent. 

In short, I observed, the one thing we had some confidence in was ... wait for it ...  wait for it .... that only the first digit of that big official number was probably right. All of the other digits in the apparently precise official count were subject to change based on the Census Bureau’s freely admitted margin of error.

I tell this story to stress that folks who do not work with numbers, day in and day out, tend to fall in love with false specificity.  

We don't have an exact count on a lot of things.  The good news even if we do not have a precise count, we have direction and velocity data, and some ballpark numbers which, in turns out, are good enough for most policy purposes. 

"Counting the uncountable" is a problem we struggle with in the illegal immigration arena, the illegal drug market arena, the nonpayment of taxes arena, and the fraud arena -- all areas I spent several decades working on in Washington, D.C.

I bring this up, because we have the same problem when it comes to counting dogs, and yet it does not matter as much as some would think, because we can gauge direction and velocity.

If numbers are going up or down, that's one thing, and if they are going fast or slow, that's another.

When it comes to population, direction and velocity is generally a more important metric than absolute numbers.