Showing posts with label experts. Show all posts
Showing posts with label experts. Show all posts

Wednesday, April 15, 2009

Recession!! (Experts Part 2)

On September 18th, 2008 a company called Lehman Brothers filed for bankruptcy. The event marked the beginning of another global financial crisis. All over the world, lives of quite a few people started changing overnight as many lost their jobs, investments burst, businesses were blowing up. Within a matter of few days everybody around started saying that major economic recession has started!

In my opinion a change, of such intensity and taking place so hastily, in the state of the world can only be justified some major natural calamity, a war, or an alien attack. It is simply incomprehensible that fall in the value of some virtual financial instruments so profoundly affects lives of people all over the world.

Why are our systems so vulnerable to such seemingly small changes beyond our control? Don’t we have any control over the situation? Who would answer these questions, our so called experts? If they were the once in charge, we shouldn’t have been here.

One of the reasons behind current global financial crisis is probably overconfidence on mathematical models by our ‘expert’ bakers. As I have understood from some of the readings in last few weeks (Sorry I can’t give exact references right now) the bankers did some foolish mistakes in using these models. Mistakes like ignoring the assumptions on which the models are based or ignoring possibility of events which even though are highly improbable can take us to a point of no return. They probably don’t believe that the world we live in is too complicated to be modeled mathematically.

Thankfully not all the experts get carried away at the same time. Here is an interesting clip of two ‘experts’ who saw this disaster coming. People like Bill Gates and Michael Dell were waiting for more than an hour to listen to these guys during last World Economic Forum.

Here is a similar example showing how unintelligent use of models can lead us to a disaster.

As explained here by Jonah Lehrer, the financial crisis has helped expose a powerful bias in human decision-making, which is our abhorrence of uncertainty.

Can we really conclude anything out of this mess? Probably nothing concrete; understanding the environment we are living in is probably beyond our intellectual capabilities. As put by Nassim Nichola Taleb in Fooled by Randomness.

“The real problem is, as I have mentioned, that such a natural habitat (the one which we are living in for thousands of years) does not include much information…. Much of our problem comes from the fact that we have evolved out of such a habitat faster, much faster than our genes. Even worse; our genes have not changed at all.”

Sunday, April 12, 2009

Experts… well, not quite (Part 1)

Note: If you don’t wish to spend your time reading a long post by a rookie, directly go to the example in the closing part of the post.

Who do we call an expert? I think somebody who has been trained in a particular field by a reputed institute and has sufficient experience in the same field. The definition is not a comprehensive one but that’s not what I want to discuss here, rather this is regarding the credibility of all those whom we can refer to as experts. This includes professors, scientists, pundits, senior engineers, and all those who occupy some ‘top’ positions in organizations. (I am very curious about why do we need to create so many levels in an organization? Assistant Vice President, Vice President, Sr. Vice President, President… common, give me a break. More about that later...)

It is very natural for any of us to turn to experts when we are faced with situations we are not confident to handle or when we want some predictions about a very complicated system. Who is more likely to form the government after upcoming elections?, how should India handle terrorism?, or how can we solve traffic problem in Pune? Even though each individual can have his own opinions about such issues; any sensible person, if put in decision maker’s shoes, would most probably discuss the matter with experts in the particular field before deciding anything. Same is true for day to day decisions, either professional or personal. An engineer facing a technical problem which he has never faced before or falls outside his expertise will most probably go to his senior. (Provided the poor fellow is not working under a prof from COEP.)

In some situations, like technical problems, the solution is objective which can be endorsed by sufficient scientific references. Most of the times, however, we are forced to take decisions which cannot be weighed against objective standards. From a minister addressing the issue of national security to a site engineer dealing with customer, each one of us faces different dilemmas.

….I just realized that I have written three paragraphs without actually coming to the point I wanted to write about. I had never faced such a situation before, whenever I was writing an essay (and it goes without saying that it was during some damn exam) I always had to keep on adding something so as to cross the minimum limit….

Coming to the point… To what extent can we really depend upon opinions/judgments of experts for making decisions, especially the ones without any objective standards?

Psychologists and neuroscientists have proved over the last four decades that we humans do not make decisions by deliberately evaluating all the possibilities, especially in complicated situations. Rather, as the great duo of Kahneman and Tversky say in their legendary 1974 Science paper (Ref 1),

“...people rely on a limited number of heuristic principles which reduce the complex tasks of assessing probabilities and predicting values to simpler judgmental operations. In general, these heuristics are quite useful, but sometimes they lead to severe and systematic errors.”

And this process of decision making is not limited to laymen, even the experts are subjected to the same for a simple reason as put by Nassim Nicholas Taleb

“We are, whether we like it or not, prisoners of our biology.”

Here is what Kahneman and Tversky say

“The reliance on heuristics and the prevalence of biases are not restricted to laymen. Experienced researchers are also prone to the same biases-when they think intuitively. For example, the tendency to predict the outcome that best represents the data, with insufficient regard for prior probability, has been observed in the intuitive judgments of individuals who have had extensive training in statistics. Although the statistically sophisticated avoid elementary errors, such as the gambler's fallacy, their intuitive judgments are liable to similar fallacies in more intricate and less transparent problems.”

I think the post is already too long to be read by any practical person. So I would stop here for today and continue with the same topic later. I will close it with following example from Fooled by Randomness.

"The following quiz was given to medical doctors

A test of a disease presents a rate of 5% false positives. The disease strikes 1/1,000 of the population. People are tested at random, regardless of whether they are suspected of having the disease. A patient’s test is positive. What is the probability of the patient being stricken with the disease?

Most doctors answered 95% simply taking into account the fact that the test has a 95% accuracy rate… Less than one in five professionals got it right."

What do you think is the right answer? Even if you don’t like probability, you should give it a best try as someday you can be the one being diagnosed.

References

  1. Amos Tversky and Daniel Kahneman. "Judgment under Uncertainty: Heuristics and Biases" Science, Sept 1974, Vol. 185 (4157), pp. 1124-1131.
  2. Nassim Nicholas Taleb. “Fooled by Randomness”.
  3. Jonah Lehrer. “How We Decide".