In the discussion so far, economics are ignored. In the last part of the
fifties decade I was at Colby College and a member of the DKE
fraternity, sometimes called "drunken dekes" disparagingly and sometimes
with admiration.  In my fraternity, about a third of the house owned
cars and seemed to have unlimited resources for "school night" runs to a
local tavern, usually for an hour or so before last call which was
midnight in Maine on week days. The majority of the house could not
afford to drink that often. We would turn down an opportunity for a late
night beer or two saying I am saving my $3 for the weekend party.  I
also recall the veterans getting their checks once a month(?) and going
on a toot and then back to their serious studying! Students have more
disposable income today, whether it is from home or from their local
jobs on or off campus. I think this plays a role in the drinking along
with some other sociological and cultural factors. cheers, Jim