Their three-factor model is one of the most popular among researchers, though many now include momentum as a fourth factor.

WSJ: Supercharging Your Investment Portfolio

Military spending fell during the fourth quarter of 2012 at its fastest pace in four decades, a key factor in the national economy's paltry 0.1% annualized growth rate, according to updated government figures released Thursday.

WSJ: Fiscal Pain to Be Parceled Out Unevenly