Entrepreneurship and Economic Growth
This article summarizes what is known about the characteristics of entrepreneurial firms. Findings indicate that the number of jobs created by entrepreneurial firm births pales in comparison to the number created by expansions of existing firms. From 1997 to 2001 there were just 161,000 net jobs created in the United States from the net of firm births minus deaths, compared to a gain of nearly 9.6 million from the net of expansions minus contractions.
Link
http://www.deed.state.mn.us/lmi/publications/trends/1105/growth.htm