For a good book on interpreting some of the Kaufman data, check out: The Illusions of Entrepreneurship: The Costly Myths That Entrepreneurs, Investors, and Poli

For a good book on interpreting some of the Kaufman data, check out: The Illusions of Entrepreneurship: The Costly Myths That Entrepreneurs, Investors, and Policy Makers Live By Scott A. Shane Cheers, Tristan