Financial Psych-Outs Part 5: The Bias Sisters
Posted by Jim Heitman on August 27th, 2010The Bias sisters can really mess with your head. If you are judging your own performance or that of an advisor these two odd behaviors can prevent you from pursuing a sound investment strategy. The Bias sisters, outcome and hindsight, are quite vain and spend most of their time looking in a mirror (a rearview mirror).
Outcome Bias
In a 1988 study Jonathan Baron and John Hershey presented participants descriptions of several different medical situations facing a doctor. The descriptions included what the doctor knew, the treatment provided, and the outcome. However, in some instances the outcome was described as a success, while in others it was deemed a failure. All the other factors (available data, treatment, etc.) were identical. Here is where the bias appears; by a factor of around 5 to 1 the successful outcome was rated as representing higher quality decision-making. This result appeared despite the fact that 88% of the participants agreed that the outcome shouldn’t be included as a factor in rating the quality of the decision. When combined with the tendency to give more weight to the most recent events (myopia) this has many investors beating themselves (or their advisors) up when the market turns against them. Even a really well considered decision can go bad, so take a deep breath and stick to the plan. Even House, M.D. loses one once in a while. Particularly if the loss was related to a macro event (market drops, housing slows, and the like) then hindsight bias comes along and beats on you some more.
Hindsight Bias
Whenever the equity markets (stocks) have a big move the market “experts” appear within minutes of the close to explain what happened. These pundits always explain events with great confidence. The impression you walk away with is that any dope should have known that was going to happen if they just paid attention. Where were all these experts before the market went south? They didn’t know either, they are just good talkers. Markets experts humbly admitting their surprise doesn’t make for good television/radio/print/internet/pod-vidcast ratings. This is where experience can help. I remember a market newsletter writer that predicted the 1987 crash. She translated that success into huge circulation for her newsletter. It would have been more impressive if she had not also predicted the crash of 1984, and 1985, and 1986. If you do not remember the crashes in 84, 85, & 86 that’s because there weren’t any.
We can see this in the news this week. There is a lot of “buzz” about the Hindenburg Omen. This technical indicator has triggered before every major market drop for years. That sounds good. However, the omen has triggered four times for every drop. Its’ accuracy is only 25%. Interesting, but not a reason to buy ammunition and hide under the bed.
Don’t let hindsight and outcome bias beat you up. The markets are by nature unpredictable and no approach works every time in all situations. Stick to your plan. There is nothing wrong with adjustments, but if the plan was sound to start with, it will likely work out just fine.
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Jim Heitman, CFP®, is a writer, speaker, Certified Financial Planning practitioner in Southern California, and the founder of Compass Financial Planning – a fee-only planning and money management firm. |




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