In "Education Pays 2013: The Benefits of Higher Education for Individuals and Society" http://trends.collegeboard.org/sites/default/files/education-pays-2013-full-report.pdf the College Board presents data for earnings, employment, job satisfaction, and other outcomes as a function of education obtained.

According to Figure 1.1, the median earnings of people by highest degree is

$91,000 PhD
$70,000 MA
$56,500 BA
$35,400 high school diploma .

Everyone should go not only to college but graduate school! (My serious advice is that gifted students should take Advanced Placement courses in high school, see if they can earn a combined BA/MA in four years, and then look for work.)

College graduates are more intelligent and disciplined on average than non-college graduates, and they would earn more even if they had not attended college. The college graduate earnings premium thus depends on the credential value of a BA, on what students learn in college, and on the characteristics of high school graduates before starting college. Reporting on earnings gaps that ignore differences in intelligence and other personal attributes is misleading.