Jim Westrich quite properly calls me to account with regard to my recent post about graduation rates. Here is what he says:
"I think my response is going to be way more nerdy than you would like but here goes. While I think as "a back of an envelope calculation" using educational attainment rates twenty years ago for those 25+ as a proxy for current educational attainment of 45+ I bristled when I read that. So, I used the CPS ASEC (March 2015) survey (this is the same data source as your linked data above) and looked at the educational attainment of those 45+ directly. The number is 30.1% so I think it is very different than the 23% of your approximation. This number is in line with other published numbers in recent years. While there are several factors that could make your method less accurate (net in-migration of college educated, lower mortality of college educated, etc.) the main issue is that there is a significant number of people completing degrees after 25. I am not immediately finding great data on this but this Gallup article gets at it somewhat: http://www.gallup.com/poll/179783/graduating-college-later-life-doesn-hamper-income.aspx I do not mean to quibble with the general point but college education is increasingly happening later in life and in "non-traditional" ways."
First of all, Jim, I cannot find the table listing "the educational attainment of those 45+ directly." Can you point me to it with a URL? Starting from that number, where did I go wrong? Obviously, by assuming that relatively few people complete their degrees after age 25. But that immediately raises a question I do not have the data to answer, viz., are these people simply finishing up at age 26 or 27 or 28, perhaps delayed because of funding problems? Or are they people who have actually left college without degrees when 19, 20, 21, 22, or 23 and then returned in their thirties or even forties to finish up? It would be really interesting to know which.
Note, by the way, that there has been a big change in college attendance patterns since I was a student. Back then, you went straight through in four years unless you were a woman who got pregnant, in which case you "went to Europe" for a year . Now, colleges, when they offer admission, routinely have a box to check if you are postponing for a year, and the standard statistic measuring a college's success with its students is the "six year graduation rate" [corresponding figure for doctoral programs is the "ten year completion rate."]
During my thirty -seven years at UMass, I saw very few over-twenty-five undergraduates, but that may be because even UMass, believe it or not, counts as "elite" in a nation of two thousand four year degree granting institutions, and I would guess that there are many more older undergraduates at the non-elite than at the elite schools. So perhaps I am making the familiar mistake of thinking that what is happening around me is typical of the world as a whole.
At any rate, thank you, Jim, for the correction, and do send me the URL if you have it.