I recently came across a book – How we decide ? This is a book about decision making and how humans make decisions under various circumstances. Although this book is not on some best seller list or by a very well known author, I found the book good and learned quite a bit from it.

Let me list some of my key learning’s from the book

– The rational brain – prefrontal cortex is involved in rational decision making and can evaluate only a limited number of variables and data elements at a time. However our emotional brain, the amygdala and other parts are the hidden supercomputers of the brain. They are able to process more pieces of information and can do so much faster. The reason is evolution. When facing an immediate danger, such as a tiger, the emotional brain had to process the information quickly and cause a fight or flight response. There was no time to sit and think in such a situation.
– The standard model of decision-making has been the rationality based model. Emotions are considered bad for decision making and corrupt our thinking process. That however is not true. Emotions can and do lead us astray, but they are crucial to decision making. The emotional brain and the rational brain are constantly communicating with each other and help us in arriving at our decisions.
– The decision process is a not a smooth process involving the rational brain alone. It is actually an argument where the emotional brain and rational brain go back and forth and based on the situation a final decision is reached.
– The learning process of the brain has a big emotional component. The dopamine system is involved in this process. Whenever we commit a mistake, the dopamine levels drop in the brain and we ‘feel’ bad about it. The emotional centers of the brain encode this memory and use it for later decision making.
– Emotions mislead us several situations. For example, the normal response to price drops in the market is fear and panic. The typical response of most of the investors is to exit the market to avoid the pain and fear. However this is often an incorrect response. A rational and calm response would be to look at the individual stocks and evaluate the expected value at the given price. A decision should then been taken based on this number, than based on emotions.

Some key learning’s for investors (my conclusions)

– Stock market investing is all about decision making under uncertainty. As investors, we can never have complete and full information. Perfect information is a myth. No one can ever know all there is to know about a company, much less an industry or the market.
– A perfectly rational investor is an incorrect model. The above book and several other books I have been reading, point out that the best investors are able to combine rational thinking with their emotions.
– Emotions are formed based on repeated experiences in a particular field. These emotions are referred to by several terms – intuition, gut feel etc. As one develops experience, the learning’s are encoded in the brain as emotions or intuitions. However one should not rely on emotions when starting out as an investor. At that time, one does not have enough experience and the emotions have not developed fully. However as one gains experience, one should learn to trust one’s instincts or at least be mindful of them.

I have personally faced this several times. When analyzing a company, all the numbers will look fine and the company looks undervalued. However some stray facts or a few points will keep troubling me. In most of the instance, where I have ignored such feelings, I have regretted later.

– Smart investing is a mix of rational thinking combined with emotional learning. As one matures as an investor, one should learn to tune in to emotions and gut feel and try to at least understand what they are telling us. You will rarely see investors talk about gut feel or emotions. They are considered too soft or not macho enough!. That is however foolish. The human brain does not work that way. Decision making is a mix of rational thought and emotions. Ignoring emotions means using only a limited power of your brain.
– Novel problems require thinking and should not be based on emotions. When analyzing a new company or business model, do not rely on emotions alone. One should think rationally and assemble all facts before making a decision.
– Embrace uncertainty – It is amazing the level of confidence most people have on their investment. Analysts writing about a company, will provide you projections for the next 3-5 years. Sometimes these projections are not even round numbers (like sales would 1244 crs in FY2010). What crap !. Nothing is absolutely certain in the stock market. There are only varying levels of certainty. To simplify it, I look at low (20-30% probability), medium (around 50%) or high level of probability (around 70-80%) for any specific scenario. In addition, I always believe in developing multiple scenarios when trying to come up with an intrinsic value number. As a result you would have noticed that my estimates are generally in a range and not a fixed number
– Entertain competing hypothesis – One should always be open to counter arguments to one’s investment idea. That allows one to accept contradictory information and weigh it properly. I try to constantly look for points, which go against my investment idea though i am not sure how successful I am at it.
– Finally think about thinking. One should constantly analyze one’s decision making and thinking process. You should be able to look at your thought process objectively and look at ways of improving it ( read this process v/s outcome article by Michael J. Mauboussin ). This blog is my approach of doing it, though in a public fashion. In addition, I always write down my investment thesis when I am looking at an idea and also how I feel about it (though I don’t publish it as they are my private thoughts).

I would strongly recommend you to read this book. It is a very good book and has several crucial points on how the human mind works and how one can improve his or her decision making.