---- Acknowledgements ----
Author contact information: email@example.com, firstname.lastname@example.org. Sari Pekkala Kerr is a senior research scientist at the Wellesley Centers for Women (Wellesley College). William Kerr is a professor at Harvard Business School and a Research Associate at the National Bureau of Economic Research (NBER) and Bank of Finland. This is a revised version of a paper prepared for the Conference on Research in Income and Wealth (CRIW) NBER meeting on December 16-17, 2014, in Washington DC and a draft chapter for the CRIW-NBER volume Measuring Entrepreneurial Business: Current Knowledge and Challenges, edited by John Haltiwanger, Erik Hurst, Javier Miranda and Antoinette Schoar. We thank our discussant Ethan Lewis, the editors, and CRIW-NBER participants for very helpful comments. We thank the Alfred P. Sloan Foundation, National Science Foundation, Harvard Business School, and the Ewing Marion Kauffman Foundation for financial support that made this research possible. The research in this paper was conducted while the authors were Special Sworn Status researchers of the U.S. Census Bureau at the Boston Census Research Data Center. Research results and conclusions expressed are the authors' own and do not necessarily reflect the views of the Census Bureau, the NSF, or the National Bureau of Economic Research. This paper has been screened to ensure that no confidential data are revealed.