New research confirms what many business owners suspected: Entrepreneurs breed entrepreneurs. Syracuse University economists Thomas A. Dunn and Douglas Holtz-Eakin find self-employed parents about three times more likely to produce self-employed children. Inheriting a business helps. Also, self-employed parents tend toward affluence, so junior's startup might get a boost. Leave out those factors, and business owners' offspring still are twice as likely to employ themselves. The key factor? Role modeling, right down to gender. Boys do as Dad did, girls tend to follow Mom.