I’ve been reading statistician Nate Silver’s 2012 book The Signal and the Noise.  He makes three points that I think are useful for us as investors:

1.  Some ostensible information sources aren’t really that.

TV and radio weathermen, for example, deliberately forecast more rainy days, and amp up the amount of rain that will fall, than they actually think will occur.  Why?  People apparently like to hear about bad weather.  Also, we only get mad if the weather is worse than predicted.  If it’s better ,we regard it as a pleasant surprise.  So there’s every reason for TV and radio to have a consistent “wet” bias–and they do.

Same thing for shows on politics.  Pundits on the McLaughlin Group, for example, have a startlingly bad record at making political predictions.  The show’s many fans don’t seem to care.  Broad, sweeping views, confidently and articulately presented, are all that matters.

It seems to me the same applies to TV financial shows.

2.  The group with the absolute worst forecasting record is professional economists.  In fact, predictions about the course of the overall national and world economies are not only highly inaccurate, they’ve gotten worse over time, not better.

In other words, don’t bet the farm on a macroeconomic forecast.

3.  Foxes are better thinkers than hedgehogs.

Silver separates forecasters into successful = foxes (he’s one), and really bad = hedgehogs.

The differences:

hedgehogs

highly specialized

“experts” on one or two narrow issues that define their careers; contemptuous of “generalists”

often in the academic world

all-encompassing theories

theory over facts

believe in a neat universe, defined by a few simple relationships

highly confident, meaning resistant to change

foxes

interdisciplinary

flexible

self-aware and self-critical

facts over theory

think the world is inherently messy

careful, probabilistic predictions.

In other words, be careful of highly confident people with overarching theories and elaborate forecasting systems.