Changes, part 1

In the 1950s, people with higher "social standing" were more likely to vote Republican.  That was true if you measured social standing by income, education, or some combination of the two factors.  Today, higher income continues to be associated with Republican voting, but college education is associated with a greater chance of voting Democratic.  One potential explanation for this change is that it reflects an increase in the importance of "social issues." More educated people have always been more liberal on social  issues, but the consensus in the middle of the 20th century was that they didn't matter very much--they would sometimes become prominent, but then would fade pretty quickly.  Basically, politics was about economic issues, and on these more educated people were more conservative.  But since the 1960s, "social issues"--e. g., abortion, affirmative action, gun control---have come to be consistently important.  So now income and education are pulling in different directions rather than reinforcing each other. 

In this account, the effects of education and income on opinions are constant--only the relative importance of different types of opinions changes.  What makes this appealing is that there are straightforward arguments for why education should be associated with more liberal opinions on social issues and more conservative opinions on economic issues,  and for why social issues should have  grown in importance.  So it rests on three points that are all clear and easy to understand.  I was reminded of this issue by  a recent column by Thomas Edsall, which points to a paper by Herbert Kitschelt and Phillipp Rehm, who argue that it explains changes in voting patterns through 2016.  They consider the possibility of change in the effects of education on opinions about economic issues, and find no evidence of it, but their data don't cover a long period of time.  In a previous post, I considered a question on redistribution from the General Social Survey that goes back to 1978.  It seemed that educational differences were declining, but I just considered education.  Suppose we take account of both income and education:

 
Positive numbers mean that higher values of income or education go with more conservative opinions on redistribution (the government should stay out of it).  The effects of income have stayed about the same, maybe declining a little, but the effects of education clearly have declined and are now near zero.  That is, it's apparently not just the relative importance of economic and social issues that has changed, but also the relationship between education and opinions on economic issues.  Why?  There's no obvious explanation.  In terms of material interests, if there was any change in the effect of education it should have been in the opposite direction, since the payoff to education has increased--that is, when you compare two people with the same income but different levels of education, the gap in expected lifetime earnings is bigger.