"Twenty-five cohorts of medical students were asked in their first and fourth year of school to estimate contemporaneous physician income in six different specialties. The students' income estimation errors varied systematically over time and cross-sectionally by specialty and type of student. The median student underestimated physician income by 15 percent, and the median absolute value of the estimation errors was 26 percent of actual income. Students were 35 percent more accurate when estimating market income in their fourth relative to their first year, which indicates medical students learn a considerable amount before choosing a specialty"--National Bureau of Economic Research web site.