Here's a good review of the economic evidence on the role of small business in employment growth. Although it's written for a Minnesota audience, the author's conclusions apply more broadly. You can read the article here [1].
The research underscores the importance of encouraging small business development in Northeast Ohio. The research underscores that employment growth is most likely to come from existing smaller firms.
Links:
[1] http://www.deed.state.mn.us/lmi/publications/trends/1105/growth.htm