The New York Times has a wonderful graphic miss-urled http://www.nytimes.com/interactive/2014/07/08/upshot/how-the-year-you-were-born-influences-your-politics.html Jon Chait points out that this URL (and a tweet) are accurate only if you are white (he doesn’t add that it only works if you are also a US citizen).
I think you will enjoy clicking the link in any case. I was struck by two radically different cohorts. White US citizens born in 1954 and in 1955. The difference is only 3% more of the younger cohort now identify as Republican, but it is quite striking compared to other differences across cohorts. What might explain the difference ?
Here are true blue elderly oldies now age 60
here are red shifting kids now age 59
Whatever could make such a difference. It couldn’t possibly be that 60 year old men received draft notices when 18 in 1972 and 59 year old men didn’t receive draft notices when 18 in 1973 could it ?
Now this places a point estimate of the utterly selfish as 6 % of men (or of roughly 3% each of men and women if one assumes that young women aren’t so selfish they they don’t mind their boyfriends being drafted). It is however, at least a tiny bit depressing.