His latest paper, published in the December issue of a journal called Decision Analysis, spells out what he believes is the right approach.

FORBES: 4 Steps to Successful Brainstorming

While fundamental factors clearly played a role in driving down house prices that were at excessive levels two years ago, we have argued in a paper (to be published in the Berkeley Electronic Journal of Economic Analysis and Policy) that in most markets house values are today lower than what is consistent with the average level of affordability in the past 20 years.

WSJ: Low-Interest Mortgages Are the Answer

They enlisted one of their fellows to do a statistical analysis, and published a Sept. 2001 paper in the Journal of the American Medical Association calling for an investigation into potential heart risks caused by Vioxx and Celebrex, a competing drug from Pfizer (nyse: PFE - news - people ).

FORBES: Behind Merck's Fall