Economist article in College Grades

The Economist Magazine carried an article: Ivy League grade inflation Grade expectations

Once again, the media demonstrates that we are in the age of HALF INFORMATION.  The article shows a chart establishing grades have gone up -- but it makes no mention of the college population demographic reality.
Consider:
USA population in 1950 was 152.3 million; in  321.2 million.  Thus the population more than doubled over this period. 
In 1950, we had a heavy post and pre-War European refugees population. 
Plus a wealth of first generation Americans who went to college because it was made possible by the GI Bill; while motivated, they lacked the modern preparation.
"For those 18 to 19 years, enrollment rates increased from 29.4 percent in 1950 to 61.2 percent by 2000."  This indicates a larger pool of applicants fo the target universities to select from.
At Harvard: "Financed by the G.I. Bill of Rights and admitted through special College entrance exams for veterans, ex-servicemen swelled the Class of 1950 to 1,645 members, more than double the past year's size."
In 2015, Harvard College admitted 1,990.
Gee, the American population more than doubled and Harvard class increases by a bit more than 20%.
NATURALLY the grade point averages would increase -- [pardon mixed metaphor] they have removed the deadwood and kept the cream-de-la-cream.
Go through the record for the other TOP schools displayed on the chart, and you'll discover the same demographic reality.