Which word is correct?
I believe today's younger generation are more attracted by flexible working hours than by the thought of earning money / wages.
(Cullen, French, and Jakeman (2014) The Official Cambridge Guide to IELTS for Academic and General Training, Cambridge University Press. p. 126)
Both words appear correct to me, perhaps "wages" sounding more formal. While Google Ngram shows "earning money" as commonly used, it shows "earning wages" as fairly common as well. The text claims "money" to be correct and "wages" incorrect. Why is "wages" not correct here?