What caused the financial crisis? The Big Lie goes viral.

I have a fairly simple approach to investing: Start with data and objective evidence to determine the dominant elements driving the market action right now. Figure out what objective reality is beneath all of the noise. Use that information to try to make intelligent investing decisions.

But then, I’m an investor focused on preserving capital and managing risk. I’m not out to win the next election or drive the debate. For those who are, facts and data matter much less than a narrative that supports their interests.

One group has been especially vocal about shaping a new narrative of the credit crisis and economic collapse: those whose bad judgment and failed philosophy helped cause the crisis.

Rather than admit the error of their ways — Repent! — these people are engaged in an active campaign to rewrite history. They are not, of course, exonerated in doing so. And beyond that, they damage the process of repairing what was broken. They muddy the waters when it comes to holding guilty parties responsible. They prevent measures from being put into place to prevent another crisis.

Here is the surprising takeaway: They are winning. Thanks to the endless repetition of the Big Lie.

A Big Lie is so colossal that no one would believe that someone could have the impudence to distort the truth so infamously. There are many examples: Claims that Earth is not warming, or that evolution is not the best thesis we have for how humans developed. Those opposed to stimulus spending have gone so far as to claim that the infrastructure of the United States is just fine, Grade A (not D, as the we discussed last month), and needs little repair.

Wall Street has its own version: Its Big Lie is that banks and investment houses are merely victims of the crash. You see, the entire boom and bust was caused by misguided government policies. It was not irresponsible lending or derivative or excess leverage or misguided compensation packages, but rather long-standing housing policies that were at fault.

Indeed, the arguments these folks make fail to withstand even casual scrutiny. But that has not stopped people who should know better from repeating them.

The Big Lie made a surprise appearance Tuesday when New York Mayor Michael Bloomberg, responding to a question about Occupy Wall Street, stunned observers by exonerating Wall Street: “It was not the banks that created the mortgage crisis. It was, plain and simple, Congress who forced everybody to go and give mortgages to people who were on the cusp.”

What made his comments so stunning is that he built Bloomberg Data Services on the notion that data are what matter most to investors. The terminals are found on nearly 400,000 trading desks around the world, at a cost of $1,500 a month. (Do the math — that’s over half a billion dollars a month.) Perhaps the fact that Wall Street was the source of his vast wealth biased him. But the key principle of the business that made the mayor a billionaire is that fund managers, economists, researchers and traders should ignore the squishy narrative and, instead, focus on facts. Yet he ignored his own principles to repeat statements he should have known were false. (more)