Everything needs a TL;DR these days doesn't it. :sigh:
The TL;DR from my comment is a) it's TSRB*L*KE (why does everyone think it's an i and that I'd only capitlize one letter?)
b) STEM is important, but the study likely blends the benefits that advance degrees (MS/MA/PhDs) have in genaral with those from specifically STEM fields. Having an Advance degree in most fields (even Non-STEM) seems to outweigh merely having STEM degree (thus a PhD in bioethics trumps my BS in biology in terms of earning potential). Though there are tons of variables to consider, admittedly.
(Yes, I realize the irony of the fact that I used skills learned during my time in a STEM field to deconstruct a study about the benefits of STEM education, which does get to Laura's point that a basic STEM eduction is defintely a good thing. I just get worried when people think a BA/BS in STEM is the only key to making large amounts of money.)
*Bioethics is basically a philopshy of science they way I study it, does that make it a STEM field?
Microsoft runs a good study, in that they managed to direct the stats the way they needed them to get Washington to throw in that extra cash. The problem on the surface is can you really compare the "STEM" fields (which typically require a college to degree, or perhaps advanced degree) to "Non-STEM" (which is a hodgepod )? The comparision is really not entirely apt. Even inside the "STEM" fields, the comparisions differ, my friends with degrees in Aerospace engineering or CS are having easier times finding jobs than my Chemist friends (But at least you're closer to an apples/apples comparison)
The data needs to be corrected for "College Degree" generally and "Level of degree" particularly. This normalization would probably eliminate much of the differences (it's well known that a college degree highly corralates with employment). But that only makes the argument for "more education" whereas MS needs "more scientists"
As an anecdotal real world example, I was in a STEM field (biochemistry) with my STEM degree (biology) for a few years. But I had a BS, which actually made my prospects not that great for career advancement (Lab tech/Lab manager is pretty much the glass ceiling with the BS). This was made worse by the layoffs happening around the nation (and paricularlly locally) in the biotech industry. A higher level degree (in this case a PhD.) would have given me more job security, but (as it turns out) that's true across several fields, so I jumped to a non-STEM PhD (bioethics) which is in growth mode and has near 0 unemployment across several programs (and more interest for me).