One of the most consuming uses of our time, in fact, has been accumulating information to help us make forecasts of all those things we think we have to predict. Where’s the evidenced that it works? I’ve been looking for it. Really. Here are my conclusions: Confidence in a forecast rises with the amount of information that goes into it. But the accuracy of the forecast stays the same. And when it comes to forecasting—as opposed to doing something—a lot of expertise is no better than a little expertise. And may even be worse. The consolation prize is pretty consoling, actually. It’s that you can be a successful investor without being a perpetual forecaster.
We have security analysts. We get research reports from brokers. We get forecasts about the economy, interest rates, the stock market. We process that information and act on the basis of it. For all of that to make any sense, we all have to believe we can generate information which is unknown to the market as a whole.
There is an approach which is simpler and probably stands a better chance of working. Spend your time measuring value instead of generating information. Don’t forecast. Buy what is cheap today. Let other people deal with the odds against predicting the future.
“Trying Too Hard”, Financial Analysts Federation Seminar 1981 [PDF]