Computer models
purported to forecast the temperature of the earth have been the source of
recent claims of anthropogenic (man-made) global warming. Substantial wealth has accrued to the
alarmist messengers of the resulting worldwide chaos. This wealth was attained either directly from presentations, a film
and investments, or indirectly from grants for continuing research. Thus these people have a vested
interest in the outputs from the models.
In the reprint below, Curmudge and Jaded Julie discuss models and vested
interests using a simple example.
Reprinted from
Curmudgeon’s Wastebasket Originally Posted February 3, 2010
“Models, Curmudge? You mean those
super-slender gals who look as if they have an eating disorder?”
“No, Jaded Julie. We’re going to
talk about mathematical models; these are mathematical depictions of
processes. Models were described in our discussions of queuing theory last
July. Authors that we cited in Kaizen Curmudgeon a few weeks ago used models to
forecast physician income in a medical home. We use value stream maps all the
time as visual models to depict processes in the hospital. The equations that I
learned in physics classes long ago were models of physical processes; they
included statics (e.g., forces on a stationary beam), and dynamics (a ball
rolling down an inclined plane).”
“Wow! There must be a model for
everything. I’ll bet that the advent of the computer has made it possible to
model processes that are more and more complex.”
“That’s for sure. We’ll talk more
about that later, but let’s start by considering a very simple example. Our
daughter moved to a new house in Madison, so I consulted MapSeek* to learn how
to get there. In addition to directions, MapSeek said that our daughter’s house
is 104.61 miles from ours and that it would take us 1 hour and 54 minutes to
get there. In computing our travel time, MapSeek must have used the model, time
equals distance divided by an estimated average speed. Their average speed was
55 mph (104.61 miles ÷ 1.9 hours).”
“I’m with you, Curmudge. Because the
MapSeek routing uses Highway 26, their average speed must have been adjusted
for slowing down in Rosendale to avoid getting a speeding ticket and perhaps
also for the possibility of getting stuck behind a farmer pulling a load of
manure on 26, a two-lane highway. But is the best route now using Highway 26
through Rosendale? U.S. 151 is now four lanes all the way from Fond du Lac to
Madison. Perhaps we should give this new information to MapSeek so they can
adjust their model.”
“That would certainly seem to be the
proper thing to do, Julie. But let’s consider this hypothetical case. Suppose
the MapSeek people own a coffee shop in Rosendale. They wouldn’t want to change
their recommended route and their model because it would hurt their coffee
shop’s business. That’s called having a vested interest in their model
and the data that go into it. MapSeek would prefer that we shut up about there
being a better route; perhaps they might even try to suppress all discussions
of alternate ways to go from Appleton to Madison.”
“Hey, that’s not fair! We all depend
on MapSeek for the correct information.”
“It’s a sad story, Julie. We can see
through what Mapseek might do because it’s hard to color the results from a
simple, transparent model based on a classical equation. In addition, Mapseek’s
work can be easily tested empirically. But when a bunch of suspect data are
poured into a complex computer model that is arcane, abstruse, and tentative,
anything can happen. That is especially true when someone has a vested interest
in the outcome.”
“(Although Curmudge uses words that
are known to only a few people and are hard for the rest of us to understand, I
get the picture.) Hey, Curmudge, your story is an allegory, isn’t it? May I
explain its lesson?”
“Go ahead, but don’t get too
specific.”
“Think critically. Be slow to accept
the conclusions of investigators attempting to model a complex process when
their work is supported—even indirectly—by people with a vested interest in
their results.”
Kaizen Curmudgeon
*Our apologies to MapQuest for using
a name similar to theirs in this totally hypothetical example.
Link to posting from blog archives: Stan’s Story 10/30/08
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