Monday, April 20, 2015

More about mobility

I was surprised by the results on educational mobility in my earlier post on the subject , so I did some more investigation.   People progress through educational categories in a definite order:  everyone starts at the lowest level and moves up one step at a time.  So you can regard educational mobility is as a series of transitions--how much does father's education predict your chance of going beyond grade school, going to high school, graduating from high school, etc.?  I estimated the association by generation for each transition.  This figure shows the first three (going beyond grade school, going to high school, graduating from high school).

There is an upward trend in the influence of father's education on all three transitions.  More exactly, there was an upward trend, although it's not clear that it's continued in the last couple of generations.

This figure shows the next two--attending college and graduating from college given that you attended.  Again, both show an upward trend.    

There's one more transition--getting graduate education--but the effect of father's education is near zero in all generations.  That is, if you've graduated from college, how much education your father has doesn't predict whether you will get graduate education.  

Although there may be some deviations, like the jump in the influence of father's education on going to college in the last generation--the overall picture is of a steady increase in the influence of father's education at all levels.  However, father's education has more influence on the lower-level transitions--the numbers on the y scale aren't meaningful in an absolute sense, but they can be compared to each other.  Given the rise in average educational levels, the lower level transitions became numerically less important--today almost everyone at least makes it into high school--and that masked the decline in mobility at each level.

That raises the question of why would there be a trend over a 100 year period, through depressions, prosperity, declining economic inequality, rising economic inequality,  urbanization, suburbanization, etc?


  1. These results seem to challenge the established MMI hypothesis. The hypothesis basically states that the effect of parents' social class on educational attainment decreases as a certain level of schooling expands close to saturation. I need to double check the literature, but these trends indeed look interesting.

    1. Looking back at some of the literature, I notice that the hypothesis started with a paradox of stability in the effects of social origins despite apparently egalitarian reforms in educational institutions. So you could argue that stability reflected two offsetting forces, and the US trend exists because American educational institutions in the 19th century were as least as egalitarian (for whites) as they are today.

    2. Wow, that make sense. I forgot the data is limited to only White men, who are obviously not the biggest winners of more recent educational expansion. Too bad GSS does not have geographical locators. It would be interesting to see how much of the rising educational inequality can be attributed to declines in rural and small town America.