The Idea in Brief

• A battle is raging about whether assets should be “marked to market” in quarterly financial statements, as opposed to reported at historical cost. Some executives blame marking to market, which is generally advocated by investors, for the financial meltdown.

• Myths are being propagated by both sides in the argument. But it’s not true that historical cost accounting can disregard permanent changes in current market value or that most assets of financial institutions are marked to market.

• Solutions that serve everyone’s needs are possible. If accounting and capital requirements were substantially unlinked, marking to market would not usually have a negative impact on a bank’s regulatory capital. Income volatility would be better understood if banks published two EPS figures—one with assets recorded at fair value and the other without. And the fair value accounting approach of “marking to model” could gain some credibility with investors if they were given the assumptions underlying these models.

What was the primary cause of the current financial crisis? Subprime mortgages, credit default swaps, or excessive debt? None of those, says Steve Forbes, chairman of Forbes Media and sometime political candidate. In his view, mark-to-market accounting was “the principal reason” that the U.S. financial system melted down in 2008.

A version of this article appeared in the November 2009 issue of Harvard Business Review.