In: Psychology
1. What is the Availability Bias? How does this bias cause problems in financial decision making? How does this basis cause problems for our lives in general? Why do we do have this bias?
The availability heuristic is a mental shortcut that relies on immediate examples that come to a given person's mind when evaluating a specific topic, concept, method or decision. The availability heuristic operates on the notion that if something can be recalled, it must be important, or at least more important than alternative solutions which are not as readily recalled. Subsequently, under the availability heuristic, people tend to heavily weigh their judgments toward more recent information, making new opinions biased toward that latest news.
The availability of consequences associated with an action is positively related to perceptions of the magnitude of the consequences of that action. In other words, the easier it is to recall the consequences of something the greater those consequences are often perceived to be. Most notably, people often rely on the content of their recall if its implications are not called into question by the difficulty that they experience in bringing the relevant material to mind
In 1985, behavioral finance academics Werner De Bondt and
Richard Thaler released a study in the Journal of Finance
called "Does the Market Overreact?" In this study, the two examined
returns on the New York Stock Exchange for a three-year period.
From these stocks, they separated the best 35 performing stocks
into a "winners portfolio" and the worst 35 performing stocks were
then added to a "losers portfolio". De Bondt and Thaler then
tracked each portfolio's performance against a representative
market index for three years.
Surprisingly, it was found that the losers portfolio consistently
beat the market index, while the winners portfolio consistently
underperformed. In total, the cumulative difference between the two
portfolios was almost 25% during the three-year time span. In other
words, it appears that the original "winners" would became
"losers", and vice versa.
So what happened? In both the winners and losers portfolios,
investors essentially overreacted. In the case of loser stocks,
investors overreacted to bad news, driving the stocks' share prices
down disproportionately. After some time, investors realized that
their pessimism was not entirely justified, and these losers began
rebounding as investors came to the conclusion that the stock was
underpriced. The exact opposite is true with the winners portfolio:
investors eventually realized that their exuberance wasn't totally
justified.
According to the availability bias, people tend to heavily weight
their decisions toward more recent information, making any new
opinion biased toward that latest news.
This happens in real life all the time. For example, suppose you
see a car accident along a stretch of road that you regularly drive
to work. Chances are, you'll begin driving extra cautiously for the
next week or so. Although the road might be no more dangerous than
it has ever been, seeing the accident causes you to overreact, but
you'll be back to your old driving habits by the following
week.
A cognitive bias is a systematic error in thinking that affects the decisions and judgments that people make. Some of these biases are related to memory. The way you remember an event may be biased for a number of reasons and that in turn can lead to biased thinking and decision-making. Other cognitive biases might be related to problems with attention. Since attention is a limited resource, people have to be selective about what they pay attention to in the world around them.
Because of this, subtle biases can creep in and influence the way you see and think about the world.
A cognitive bias is a type of error in thinking that occurs when people are processing and interpreting information in the world around them. The human brain is powerful but subject to limitations. Cognitive biases are often a result of your brain's attempt to simplify information processing. They are rules of thumb that help you make sense of the world and reach decisions with relative speed.
When you are making judgments and decisions about the world around you, you like to think that you are objective, logical, and capable of taking in and evaluating all the information that is available to you. Unfortunately, these biases sometimes trip us up, leading to poor decisions and bad judgments