When it comes to healing hearts, marriage may be powerful medicine, but it's in increasingly short supply, Idler says, which does not bode well for aging baby boomers.
Regarding your title, people is a countable noun. For that reason you would have to say fewer people, rather than less people.
And 'in short supply' doesn't mean 'increasingly' anything; there's just not much of it about. The quantity may indeed be decreasing steadily - but the phrase doesn't necessarily imply that.
Last edited by BobK; 16-Mar-2012 at 15:45. Reason: Fix typo