"It profits me but little that a vigilant authority always protects the tranquillity of my pleasures and constantly averts all dangers from my path, without my care or concern, if this same authority is the absolute master of my liberty and my life."

--Alexis de Tocqueville, Democracy in America

Wednesday, August 31, 2011

Science, Experts, Models and Uncertainty

Our society tends to think of science as high school physics class, and maybe as the first week of high school physics class.   You have plastic pucks on an air table, which should create the illusion of a frictionless surface, and you bounce them off of each other and you study two dimensional motion, collisions, angular momentum, torque, center of mass, etc.   But the world isn't two-dimensional, and the number of variables in real world problems is infinite.

For instance, consider this article from The Fiscal Times:
What caused the financial crisis that is still reverberating through the global economy? Last week’s 4th Nobel Laureate Meeting in Lindau, Germany – a meeting that brings Nobel laureates in economics together with several hundred young economists from all over the world – illustrates how little agreement there is on the answer to this important question.

Surprisingly, the financial crisis did not receive much attention at the conference. Many of the sessions on macroeconomics and finance didn’t mention it at all, and when it was finally discussed, the reasons cited for the financial meltdown were all over the map.

It was the banks, the Fed, too much regulation, too little regulation, Fannie and Freddie, moral hazard from too-big-to-fail banks, bad and intentionally misleading accounting, irrational exuberance, faulty models, and the ratings agencies. In addition, factors I view as important contributors to the crisis, such as the conditions that allowed troublesome runs on the shadow banking system after regulators let Lehman fail, were hardly mentioned.

Macroeconomic models have not fared well in recent years – the models didn’t predict the financial crisis and gave little guidance to policymakers, and I was anxious to hear the laureates discuss what macroeconomists need to do to fix them. So I found the lack of consensus on what caused the crisis distressing. If the very best economists in the profession cannot come to anything close to agreement about why the crisis happened almost four years after the recession began, how can we possibly address the problems?
What?   Nobel Prize-type economists don't understand how the financial crisis occurred?   Our experts upon whom we rely so much lack expertise on the essential issue?   Really?   The same experts who told us that if we borrowed, oh, a trillion fucking dollars from our grandchildren, then the economy would recover?

Or consider this, similar point, from an article about Hurricane Irene:
The computer models, and the meteorologists who wielded them, put in a "gold medal" performance when it came to predicting Irene's track — but there was much more uncertainty about the intensity of the storm. That's typical for tropical storms, said Frank Marks, director of the Atlantic Oceanographic and Meteorological Laboratory's Hurricane Research Division. "Irene really exemplified the issues that we've been trying to tackle," he told me.

Hurricanes typically follow a pattern in which an outer ring of storms will tighten up to replace an inner ring surrounding the hurricane's eye, intensifying the storm system in the process. In Irene's case, that pattern (known as eyewall replacement) was interrupted, and the storm didn't gather as much strength as most of the models suggested. "Some of the models did represent it well," Marks said, but there wasn't enough confidence in those models to change the storm forecast.

Researchers have been working to reduce the error rate for hurricane track and intensity forecasts through the Hurricane Forecast Improvement Project, with the goal of a 50 percent reduction from 2008 levels by 2018. The University of Washington's Cliff Mass, an expert on weather modeling, said Irene showed that much more progress still has to be made on predicting a storm's intensity.

"The classic is good forecast for track, bad forecast for intensity," he told me. "Let's face it: This happens all the time. ... To get the intensity right, you have to be able to predict the inner workings of the storm, and that's what we don't do well yet."
What?   The meteorology experts who have been telling us for years that global warming will make the seas rise and devastate the planet can't tell us how hard the wind will blow in a storm?   Really?  

An intelligent citizenry listens to experts when they have demonstrable expertise in their fields.   I listen to doctors in deciding how to treat my children's illnesses, for instance.   But an intelligent citizenry should be highly skeptical of so-called "experts" who purport to have answers to questions whose variables are so numerous and complex as those that govern the functioning of our economy or long-term weather patterns.  

And we should be extraordinarily skeptical of so-called "experts" whose solutions to problems involve taking money from taxpayers and arrogating power to themselves.

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