“…Studies employing this approach generally found significant positive returns to medical education. However, depending on the time period of observation, the particular physician specialties, the comparison occupations, and the estimation technique, the estimated returns to education varied widely (Burstein & Cromwell, 1985;Friedman & Kuznet, 1945;Leffler, 1978;Leffler & Lindsay, 1980;Lindsay, 1973;Marder & Willke, 1991;Maurizi, 1975;Weeks, Wallace, Wallace, & Welch, 1994;Wilkinson, 1966).…”