21/06/2021
Why Investors Are Irrational, According to Behavioral Finance
Traditional vs. Behavioral Finance
Established economic and financial theory posits that individuals are well-informed and consistent in their decision-making. It holds that investors are “rational,” which means two things. First, that when individuals receive new information, they update their beliefs correctly. Second, individuals then make choices that are normatively acceptable. While this framework is appealingly simple, it’s clear that in reality, humans do not act rationally. In fact, humans often act irrationally–in counterproductive, systematic patterns. 80% of individual investors and 30% of institutional investors are more inertial than logical.
These deviations from theoretical predictions have paved the way for behavioral finance. Behavioral finance focuses on the cognitive and emotional aspects of investing, drawing on psychology, sociology, and even biology to investigate true financial behavior.
Behavioral Biases and Their Impact on Investment Decisions
We all have strongly-ingrained biases that exist deep within our psyche. While they can serve us well in our day-to-day lives, they can have the opposite effect with investing. Investing behavioral biases encompass both cognitive and emotional biases. While cognitive biases stem from statistical, information processing, or memory errors, an emotional bias stems from impulse or intuition and results in action based on feelings instead of facts.
Overconfidence
In general, humans tend to view the world positively. Outside of finance, in a 1980 study, 70-80% of drivers reported themselves to be in the safer half of the distribution. Multiple studies – of doctors, lawyers, students, CEOs – have also found these individuals to have unrealistically positive self-evaluations and overestimations of contributions to past positive outcomes. While confidence can be a valuable trait, it can also lead to biased investing decisions.