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sakky, the prospective engineer phds drop out because they can't hack it at grad schools or they're just sick of grad school (they would've gotten a phd had they wanted)?
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<p>Probably more of the latter, although the two reasons are somewhat intertwined. While relatively few PhD students are actually expelled from their programs involuntarily, many of them find out that they are interested in something else and hence just don't have the desire to put in the work to complete the program (although they probably could if they really wanted to). For example, they see their old undergrad buddies who went straight to industry and who are progressing along nicely in their careers and decide that they ought to do the same. Similarly, many PhD students decide that they'd rather get a more marketable degree such as a law degree or MD. Some grad students are able to find the job that they want without having to finish their programs. This seems to be quite common in some technical programs, i.e. arguably the greatest attrition "threat" to Stanford EE/CS grad students consists of students deciding to drop out to launch their own startup firm. Finally, and probably the biggest threat of all, is that many grad students get married, have kids, and then decide that they would rather invest their time in their families.</p>