The Association of American Colleges & Universities includes a report on long -term salaries for liberal arts graduates and how they are compared with graduates in engineering and other professional fields.  The report here claims that while liberal arts graduates have more difficulty finding jobs right after graduation, their earning power increases steadily until it reaches that of graduates of professional programs.

www.aacu.org/pres_room/press_releases/2014/liberalartsreport.cfm