Posts filed under “Mathematics”

Buffett on Stock Prices

Its early in this potential correction, but let me remind you of Buffett’s interesting (1997) comments:

“If you plan to eat hamburgers throughout your life and are not a cattle producer, should you wish for higher or lower prices for beef?

Likewise, if you are going to buy a car from time to time but are not an auto manufacturer, should you prefer higher or lower car prices?

These questions, of course, answer themselves. But now for the final exam: If you expect to be a net saver during the next five years, should you hope for a higher or lower stock market during that period?

Many investors get this one wrong. Even though they are going to be net buyers of stocks for many years to come, they are elated when stock prices rise and depressed when they fall. In effect, they rejoice because prices have risen for the “hamburgers” they will soon be buying. This reaction makes no sense. Only those who will be sellers of equities in the near future should be happy at seeing stocks rise. Prospective purchasers should much prefer sinking prices.”

–Warren Buffett, chairman’s letter, Berkshire Hathaway annual report, 1997 

Its worth thinking about, regardless of whether the recent investor nervousness turns into something more significant . . .


Category: Bad Math, Investing, Philosophy

The NY Post’s Financial Innumeracy

@TBPInvictus here: The New York Post ran a piece on Netflix (NFLX), written by Claire Atkinson, that was, to put it charitably, interesting. And by interesting I mean that it painfully misstated the very simple mathematics of stock splits. The piece implied that NFLX is wildly overvalued. I have no problem with that. Not that…Read More

Category: Bad Math, Cognitive Foibles, Data Analysis, Financial Press, Really, really bad calls

Fine, when you ignore history

This must be the “new normal” everyone​’s talking about​. Where a cyclical low ​in the ​unemployment rate​, to the the low 5 percent range​,​ is met with a courtly high stock market and talks of an impending rise in rates. Sure there is a feeling in some pockets ​of the economy ​that “things” are much…Read More

Category: Bad Math, Economy, Think Tank

More Fun With Useless Correlations: American Pharoah

About a year ago, we discussed what happens “When Correlations Lie.” Delving into the classic logical fallacy that correlation implies causation, we looked at equities and a variety of supposedly related factors, including gross domestic product, rising interest rates, earnings surprises, new financial products and the “death cross” involving daily moving averages. All were classic coincidences of…Read More

Category: Bad Math, Cognitive Foibles, Investing

Cullen Roche vs Andrew Smithers on Tobin’s Q

I love this debate between the idea of Tobin’s Q-Ratio as th be all for valuation analysis. It is embodied between Smithers & Co. quoted in this scary BBRG article and Pragmatic Capitalism’s Cullen Roche. Here is PragCap: “Better yet, look at the number of times this ratio has been cited during the most recent bull market…Read More

Category: Bad Math, Data Analysis, Investing, Valuation

A Face in Numbers: Microsoft, Google & Big Data

Salil Mehta is a statistician and risk strategist. He served for two years as Director of Analytics in the U.S. Department of the Treasury for the Administration’s $700 billion TARP program. Salil is on the Editorial Board for the American Statistical Association, is a Chartered Financial Analyst, a fellow member of the American Statistical Association and…Read More

Category: Mathematics, Think Tank

Death Tax, Paying for What You Use, Comment Foolishness

There was some pushback on yesterday’s rather tame suggestion that the U.S. properly finance the fund that pays to maintain and repair our roads. Much of the correspondence was surprising. Then again, I am continually flabbergasted by the cognitive errors that the human brain can make. It’s a marvelously designed piece of wetware that does a…Read More

Category: Bad Math, Politics, Taxes and Policy, Weblogs

Probability, Mean Reversion and Forecasting

We’re down to the Final Four in this year’s iteration of March Madness, also known as the national collegiate basketball tournament. Our earlier discussion of “The March Madness Theory of Investing“ didn’t sit well with some readers. The lessons we sussed out from the bracket-destroying results included home-country bias, how expert forecasts are about as good as those…Read More

Category: Apprenticed Investor, Bad Math, Psychology, Sports

Momentum vs. Mean Reversion

Salil Mehta is a statistician and risk strategist. He served for two years as Director of Analytics in the U.S. Department of the Treasury for the Administration’s $700 billion TARP program. He is the former Director of the Policy, Research, and Analysis Department in the Pension Benefit Guaranty Corporation. Salil is on the Editorial Board for the…Read More

Category: Investing, Mathematics, Research

Dilbert: Beating the Average

Source: Dilbert

Category: Bad Math, Cognitive Foibles, Humor, Investing