Editor's note: Michael Trotter, who has worked for two big firms, founded two firms and now works for the new-model firm Taylor English Duma, is a keen analyst of the economics of law practice.

Trotter wrote his first history of the legal profession in 1997, “Profit and the Practice of Law,” warning that Big Law had shifted from a profession to a profit-driven industry. His 2012 follow-up, “Declining Prospects,” cautioned that this economic model was not sustainable and predicted some big firms would get squeezed out by expanded corporate law departments and more affordable midsize firms.

This year he published “What's To Become of the Legal Profession?” In the excerpt below, reprinted with his permission, Trotter explores what he calls “The Elite Firms”—firms that are part of The Am Law 100 that meet criteria he thinks set them apart.