Inquiry from a reader: "When did youth become the plural of youth? Is one accosted by a pack of youths, or a pack of youth?"
Youth has the status of a count noun (one youth, two youths)* and a mass noun (we have fretted about American youth, one cohort after another, since the Fifties). What strikes me as novel, and mildly disagreeable, is blurring the distinction in academic-bureaucratic jargon.
Examples are plentiful at the Corpus of Contemporary American English: "The percentage of youth experiencing unwanted exposure to pornography declined from 34% in 2005 to 23% in 2010." "Children and youth with emotional and behavioral disorders." "A comparison of youth with and without SLD." "The community college and the entry point to higher education for youth and adults who are historically underrepresented."**
Thanks to journalists, for whom it is easier merely to echo the sources rather than to convert their jargon into common language, this mass-noun-youth-as-count-noun tic is bleeding into common discourse.
As editors, we should be reflexively suspicious of jargon. There is technical language in medicine, science, and the other professions that is necessary for precision. But some jargon merely exists to identify the in-group from outsiders. When a reader is confronted with a piece of jargon that could just as easily be rendered in common English, it transmits the message that the reader is an outsider pressing his nose against the window to look at the experts at their important work.
Besides, every piece of jargon makes your text that much duller.
*You will recall Joe Pesci's references in My Cousin Vinnie to "two yutes."
**Every time I come across one of these references, I think of youth as an amorphous, faceless swarm.