We all know women are starting businesses at a fast clip, but privately a growing number of policymakers and business leaders express skepticism about the importance of that trend. The reason: census numbers that suggest most women-owned companies have insignificant revenues and generate few jobs. What the skeptics don't seem to realize is that census figures do not include women-owned corporations, the organizational form of choice for almost all dynamic enterprises. "We think the census misses at least 1 million women-owned businesses, all corporations," says Sharon Hadary, executive director of National Foundation for Women Business Owners. "Then large companies look at the data and just don't see a market there. As a result they don't take this portion of the economy seriously enough." Hoping to remedy the situation, the foundation has contracted with Cognetics Inc., the Cambridge, Mass., consulting firm founded by David Birch, to produce a study of women-owned corporations. The data will be released early in 1992. Stay tuned.