I don't watch cable business news very often, but when I do, I soon find myself writing an article about how obnoxious it is.

I got rid of cable a few years ago and never looked back. Part of the reason was, as a business writer, I was glued to financial news to an unhealthy degree. It's as dangerous as it is addictive. "The calamity of the information age is that the toxicity of data increases much faster than its benefits," writes Nassim Taleb.

But I was traveling last week, and couldn't resist flipping on the hotel's TV to my dear old friend, CNBC. There I was met with rapid-fire opinions from analysts -- half of whom are curiously employed by eponymous firms -- debating where the price of oil is headed, and what the S&P 500 will earn over the next two years.

In a world of breathless predictions, the most valuable tool might be Google Archive, which allows you to go back in time and see how old prophecies fared. We don't do this enough. The ultimate value of any forecast isn't whether it sounded nice. It's whether it eventually becomes correct. Spend some time in Google Archive, and you can't help but notice that the vast majority of forecasts about the economy or the stock market are utterly wrong in hindsight.

Our cable analysts opined about the future of oil and earnings. So it's worth looking at how popular opinions about these topics fared in the past.

Let's start with oil.

In the late 1990s, oil cost about $13 a barrel and a gallon of gas was less than a buck. Analysts' consensus was that it would stay that way. A 1998 Associated Press article explained that oil prices were likely to remain depressed "into the next decade, with no full recovery until after 2007." The Energy Information Agency predicted that after 2007 oil prices would trade no higher than $20 a barrel. That was on the bullish end; a 1999 New York Times article reminds us that "Oil company executives told Congress that prices would linger around $10 a barrel for the next decade." The reason for cheap oil was simple: Asia's economic crisis was "expected to help keep gasoline prices low for at least the next decade," The Kansas City Star wrote.

Whoops. Prices skyrocketed to $140 a barrel by 2008 -- 14 times the oil industries' own estimate a decade before. Much of the rise was due to heavy demand from... Asia.

Then the consensus did a 180. Dig through the 2008 archives and you find forecasts like this, from the Financial Times: "Gazprom, Russia's gas monopoly, on Tuesday predicted oil prices would reach $250 a barrel in 2009." The New York Times profiled a prominent analyst who foresaw "a 'super spike' -- a price surge that will soon drive crude oil to $200 a barrel."

Whoops again. Oil crashed to $31 a barrel within months.

Then opinions flipped anew. The Times wrote in early 2009: "Some are predicting that oil could fall to $20 a barrel and stay low for years."

Funny thing: It was back above $100 a barrel earlier this year.

The most accurate way of handling analysts' oil projections over the last decade was to multiply or divide them by five. Can we just admit that no one knows what oil will do in the future?

Now let's talk S&P 500 earnings.

It's 2007, and the stock market is booming to an all-time high. Analysts foresee the S&P 500 earning $94.20 in 2008, a new record. "It's a really good investing environment in general right now," an analyst tells Bloomberg. In fact, it was one of the worst in history.

The S&P ended up earning half the amount analysts expected in 2008, and stocks plunged nearly 50%. Another whoops.

By 2009 gloom was pervasive. Bloomberg lamented "the longest earnings slump since the Great Depression." Analysts expected the S&P 500 to earn $53 a share in 2010, and $63 in 2011.

In reality, the index earned $83 and $96, respectively. Here again, for the last five years you could have been a top performer by taking analysts' earnings estimates and multiplying or dividing them by two. Can we just admit that no one knows what earnings will do in the future?

Nobel-winning psychologist Daniel Kahneman recently remarked: "Many people now say they knew a financial crisis was coming, but they didn't really. After a crisis we tell ourselves we understand why it happened and maintain the illusion that the world is understandable. In fact, we should accept the world is incomprehensible much of the time."

The value in calling out bad predictions isn't to point fingers at those who have gotten it wrong. It's to point fingers at those who listen to and put faith in those predictions, assuming that suddenly, this time, experts can accurately see the future when history shows -- conclusively -- that they can't. It's not the experts, but the people who listen to the experts, that are the real fools.

Check back every Tuesday and Friday for Morgan Housel's columns on finance and economics.