Quartz: But not all degrees are equal. by Allison Schrager
'An engineering major will probably earn more than a philosophy major. It’s also a bigger investment.
'A new paper estimates how much it costs to educate students in different fields. The economists looked at education costs and future earnings from undergraduates that came through the University of Florida system. They estimate it typically costs the universities more than $62,000 to educate an engineer (including professor salaries, facilities fees, and administrative costs). The price to educate an English or business major is nearly half that.
'Engineering degrees cost about 40% more than the lowest-cost majors; that difference can mostly be attributed to higher personnel costs. Engineering majors also need more expensive indirect resources: advising, administration, financial aid, plant maintenance, library costs, and student services.'
"The Costs of and Net Returns to College Major" by Joseph G. Altonji and Seth D. Zimmerman here
"STEM Attrition: College Students’ Paths Into and Out of STEM Fields" by Xianglei Chen and Matthew Soldner (pdf) here