Size does matter. Up to a certain point, the more widgets you produce, the cheaper each widget becomes. But you no longer have to be General Motors to reap economies of scale. Several recent studies suggest a Goldilocks effect: medium-sized companies enjoy the benefits of scale more than the big ones do.

The new funding rules are creating a "Goldilocks effect," explained Henry Savath, vice president at A. Foster Higgins Co., the employee benefit unit of Johnson & Higgins, New York. "It can't be too great, it can't be too little, it has to be just right."