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Tannor Pilatzke
Tannor Pilatzke
Articles (76)  | Author's Website |

The Perceived Value of a Forecast

January 13, 2014 | About:

While the end of 2013 has come and gone, and the New Year has been ushered in, I have found my self once again pondering over the complexities involved in forecasting. I have been thinking more specifically about how those forecasts/predictions/estimates may be both beneficial and toxic to the perception of the interpreter. There have been more forecasts than I can count in the last few weeks, ranging from individual stocks picks, to the North American markets as a whole, followed by the macro picture in the emerging markets and China, U.S Treasuries, 3-D printing, gold, bitcoin, USDJPY, USDCAD and pretty much everything else under the sun.

This year I have (hopefully) learned more from the biases that manifest within predictions, from what I will call the “utility of predictions” and the self-cancelling/fulfilling (asymmetric) affects of the predictions (the premise of the article). The purpose will be much more philosophical than scientific, as much remains unknown regarding how predictions affect our decisions, or the “utility of the prediction” and how it can be quantified.

We will start off with a few failed predictions over the last quarter century that may have had an influence on economic outcomes, consisting of recessions, the 1981 Peru earthquake, farmers and weather.

Recession Predictions

Most people have heard of the old saying that economists will have predicted nine of the last six recessions. Or maybe the saying, even a broken watch is right twice a day.

What those statements don’t say are the affects of having the wrong time for the other 1,438 minutes in the day or how market participants’ decisions will be affected by the other three recession forecasts.

“Charlie and I believe it’s a terrible mistake to try to dance in and out of it based upon the turn of tarot cards, the predictions of 'experts,' or the ebb and flow of business activity. The risks of being out of the game are huge compared to the risks of being in it.” -Warren Buffett (Trades, Portfolio)

Clearly economists do a terrible job (outlined above), and it is sometimes argued they actually add negative value. The question I am trying to answer here is how do economists (or other) predictors influence our actions and to what degree? I read an interesting study recently on weather and farmers' decisions and found a few key things peculiar: how much they were influened and by what.

Weather and Farmers

The table above shows current and recent past conditions (CRPC), the short-term forecast (STF) and the long-term forecast (LTF). The numbers below are on a scale of 0 to 7, representing the utility of the forecast to farmers. Farming decisions were categorized into five groups corresponding to different stages of crop production: 1) agronomic decisions through planting (including choice of crop type, seed variety, tillage method, planting density, and date), 2) summer growing-season decisions (including applications of pesticides, herbicides, fertilizers, and irrigation), 3) harvest and postharvest decisions (including harvest date, autumn irrigation, and tillage), 4) crop insurance, purchased before the March 15 federal deadline of each year, and 5) marketing choices made throughout the year. The study characterized this outcome of utility by the following grouping of 10 descriptions,. i.e the value of each to the farmer: 

  • Planting the best crop and variety; optimum spring tillage; best planting density and planting date.
  • Right amount of crop insurance.
  • Optimal amount of spraying, fertilizing, and water applied (used); best harvest date.
  • Maximizing crop revenue from marketing.
  • Lowest possible costs of production.
  • Reducing financial risk.
  • Sharing limited sources of irrigation water with others.
  • Reducing fertilizer and pesticides in runoff/ground water.
  • Sustaining rural communities.
  • Others (please specify).

As we can see from the study (the two pictures provided above), forecasting and past trends were clearly influencing the utility of the decision for the farmers from various sources, although some more than others (like the spouse or television and radio). There are also other various social norm weightings shown above; we can infer how influential a spouse and television/radio can be compared to others. (The scale is 0-49.) 

The stronger the signal is perceived (or the more the forecaster is trusted to be accurate) the longer the signal will last. Attraction and repulsion laws will run there course and as more people are influenced by a particular forecast, the more likely they are to add to it, alter it or simply claim it as their own, causing an exponential function to the forecasts growth, or in a sense, self-fulfilling.

You may be asking, well, why does any of this matter? Why do I care? How can it benefit me? Well, think of how these simple everyday predictions are correlated with psychological sentiment (pessimism and optimism) the higher the emotional function, the more attraction or repulsion; the stronger the signal, the higher the utility of the forecasts. These are what I like to mentally visualize as the extremes of the investor emotional pendulum that is forever (albeit asymmetrically) swaying back and forth. If we want to exploit these extremes of emotion we must become students of our own (and others) pysche/emotion, conducting metacognitive thinking excersises. 

We should ask and think probabilistically, do all the inputs create a signal or are they simply noise? Do the inputs affect my Bayesian prior in a material manner? Take the prediction by Bailey Willis of the 1981 earthquake in Peru that was supposed to be 9.9 in magnitude. This prediction ended up causing mass hysteria and real-estate prices to plummet simultaneously across the country although no serious earthquake came. These types of forecasts can have such strong affects of attraction that they become self-fulfilling, or so repulsive that they become self-defeating, hence the term "self-fulfilling prophesy."

In the case of the earthquake, nature does not care about our perception or beliefs of an event, and nature produces no effect from the causation of our thoughts. Humans are quite different as we can/will influence others' perceptions through our own narratives, predictions and beliefs. This of course is in the present or future tense and our confirmation bias, hindsight bias and narrative fallacy, all help to dilute the objective event as it passes into our own subjective perception. Mirror neurons further complicate what we believe, percieve and learn as we subconsciously/implicitly absorb others' language, choices and actions.

I fee like I am rambling, and I will move to wrap up the conversation with a summary of a few main points.

  • Crowd wisdom may be flawed when the collective judgment is weighted inconsistently, giving certain variables higher or lower weights than others.
  • Forecasts can be self-fulfilling and self-defeating; what is the incentive of the forecast, is there any skin-in-the-game?
  • We all deliver some utility in what we believe and care to share about our beliefs; there is perceived value to a forecast
  • Hindsight bias, confirmation bias and narrative fallacy cloud our judgment about past events and how we perceive them.
  • We need to weigh forecasts probabilistically against our prior perceptions.
  • Do not make forecasts if you do not understand who you may be affecting and how their decisions may be impaired as a result; a forecast is not something that should be taken lightly.

Finally, we should not forget that 90% of all communication is non-verbal and our actions can speak profusely louder than our words. When a certain threshold of forecast-correlation becomes (implicitly) present, we will likely be affected. It takes much practice and experience to become a stoic contrarian.

Further Reading:

A great book I read recently covering forecasts and our inability/fallibility of predicting was, “The Signal and The Noise: Why So Many Predictions Fail – but Some Don’t” by Nate Silver.

Another great article from National Geographic I read recently and would recommend was about collective behavior in ants, bees and flocks of birds.  

Swarm Intelligence is decentralized, self-organized Collective Behavior.

About the author:

Tannor Pilatzke
I am a self taught investor through Warren Buffett, Charlie Munger, Ben Graham, Peter Lynch, Joel Greenblatt, David Einhorn, Seth Klarman, Howard Marks, Phillip Fisher and Thornton O'Glove. My focus is a bottoms up Value-GARP strategy with a mix of top down contrarianism.

"When you find yourself on the side of the majority, it is time to pause and reflect." - Mark Twain

Visit Tannor Pilatzke's Website

Rating: 4.2/5 (9 votes)


Superguru1 - 3 years ago    Report SPAM

"The risks of being out of the game are huge compared to the risks of being in it."

I learned that the hard way last 2 years.

Tannor - 3 years ago    Report SPAM

I am sorry to hear Ashish, sometimes we must learn some things ourselves. It also easier to say with hide sight bias what should of been done but it will drive you crazy. We have to play the hand we are delt the best way we can, much like poker, you are not wrong because you lose money and you are not right because you gain money. What matters is that the process was correct. I could say with hind sight bias I should have levered to the moon with LEAPS and borrowed money, but this process is clearly a flawed one over the long-term. Owning a pieace of a businesses is all investing is on the most basic level, if the collective universe of businesses are all overvalued on average it does not mean they are all overvalued and a deal can not be found.

There is a funny joke statisticians tell, "The confident statistician crossed a puddle that was on average 3-feet deep, he drowned."

AlbertaSunwapta - 3 years ago    Report SPAM

Forecasts are fun to read to see what factors are being considered, thus pointing to a range of outcomes despite the 'fact', that it's highly unlikely that any forecast will be very accurate.  The value is in opening up one's mind to the possibilites as we all inherently have a forecast buried in our minds of what is to come.  

Buffett himself talks of his optimistic view of the US in the future.  And there's absolutely nothing wrong with that.  Despite what he himself says, there's still a chance that he will be right.  Since none of us truly can know, why not adot the most optimistic view of the future and enjoy life while it lasts.  

Some great quotes for you:

“The only function of economic forecasting is to make astrology look respectable.” - John Kenneth Gaibraith (economist)

When asked; Why do economists forecast when they have such a poor record of successful forecasting, I believe Gailbrath also said: "Because people ask them to."


"I am reminded of the story Nobel Prize winner Ken Arrow tells about his experience trying to make long-range weather forecasts for the military during World War II. He told his superiors that his forecasts were so unreliable as to be useless. The word came back that the General knew his forecasts were useless, but needed them anyway for planning purposes. " - Bill Miller, 

"The ideas of economists and political philosophers, both when they are right and when they are wrong, are more powerful than is commonly understood. Practical men, who believe themselves to be quite exempt from any intellectual influences, are usually the slaves of some defunct economist." - JM Keynes


A further comment. Regarding the earthquke prediction probability commentary below, it shows how prections can be wrong, however if one looks at eruption predicatability, Mt. Pinatubo and Mt. St. Helens predictions saved hundreds of thousands of lives.  My understanding was that the Mt. Pinatubo prediction was quite the feat of anaysis.  Bottom line: Better safe than sorry.  "Rule number 1: Never lose money, Rule Number 2: Never forget Rule number one." - Buffett  Moreover, Buffett has said he thinks every day about what may go wrong.  He really watchs the downside and I suppose that is a prime determinant of why he's had such a great upside.

"Take the prediction by Bailey Willis of the 1981 earthquake in Peru that was supposed to be 9.9 in magnitude. This prediction ended up causing mass hysteria and real-estate prices to plummet simultaneously across the country although no serious earthquake came. These types of forecasts can have such strong affects of attraction that they become self-fulfilling, or so repulsive that they become self-defeating, hence the term "self-fulfilling prophesy."

Tannor - 3 years ago    Report SPAM

Thanks for the comments Alberta,

I espiecaly like the quote by JM, Keynes.

I completely agree with opening your mind to advise, other opinions or predictions. The problem though I might add is that these are all things that are given away freely, we must be careful we only consume what the opinions/advise/predictions worth having (paraphrasing Richest Man in Babylon)

Again I whole heartedly agree that it is healthier to have an optimistic skew to life, part of the reason I identify as a skeptical optimist.

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