Worth a read. WSJ https://www.wsj.com/articles/some-professional-degrees-leave-students-with-high-debt-but-without-high-salaries-11638354602?reflink=share_mobilewebshare Summary in case WSJ is not accessible: https://www.yahoo.com/news/youre-taking-student-debt-rich-200034859.html
When they say "professional degrees," they mean "first professional degrees." Professional degrees are academic, pointed towards practice instead of scholarship. (Ex: EdD and DBA.) First professional degrees are used to enter certain professions like the ones noted in the article.