Economics, Literature and Scepticism

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I am a PhD student in Economics. I am originally from South Africa and plan to return there after my PhD. I completed my M. Comm in Economics and my MA In Creative Writing (Poetry) at the University of Cape Town, where I worked as a lecturer before starting my PhD.

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Tuesday, September 23, 2008

Who You Marry and Persistent Inequality

Posted by Simon Halliday | Tuesday, September 23, 2008 | Category: , |

Lane Kenworthy, a professor at the University of Arizona, Tucson, spoke at the CRISS workshop which I attended this last weekend in Rome. I will comment briefly on one of the concepts, marital homogamy, that he introduces in the first chapter of his book Jobs With Equality which is available online. I know that this concept is not new, I know that my discussion of it is not revelatory, I just wonder what people think about the problems that such a phenomenon creates.

Marital Homogamy, which I think is becoming more and more important Worldwide, and will probably become an increasing problem in South Africa. So what is marital homogamy? It is the tendency for individuals of similar levels of eduction to pair up as life-partners, i.e. that those with high education tend to marry or cohabit, and those with low education tend to marry or cohabit. This has persistent and damaging effects to equality. Now let us consider too that there are peer, neighborhood and heritability effects going on (through genetics, or upbringing, what you will). Thus, it is quite feasible that there will be even stronger persistence of inequality over time.

Why is this? If there is a high level of inequality, combined with a high level of marital homogamy with high levels of high heritability and peer/neighborhood effects, then parents with high education will have children who have high levels of education and consequently, higher levels of income. Call marital homogamy the degree of correlation of individuals. Hence, a high level of marital homogamy will result in a higher degree of income inequality persistence, lower correlation will be correlated with lower inequality persistence. Inequality will persist as long as there is a high level of positive correlation of individuals through education.

How do you intervene in such a situation? What do we do to combat the problem of positive sexual selection by certain characteristics such as level of education? Well, in my mind we cannot legitimately intervene by `preventing' the marriage of individuals who have similar levels of education. This would also create odd incentives, for example they could choose to cohabit and not marry if 'marriage' was the point of intervention. Notwithstanding this funny incentive structure for not marrying, the infringement on individual freedoms would be, for me, problematic. Where else can we attack the problem? Well, how about taking a look at the extent to which characteristics are 'inherited', or affected by peer and neighborhood effects. Let's go along with the literature and say that these effects are strong and positive. Should we disallow school selection by parents and randomly allocate students to schools? Probably not. In all likelihood you would have out-migration of parents with high education who have the most to `lose' in this situation. The reason I say this is that it is unlikely that any policy we enact would allow simple `upgrading' of uneducated individuals to `educated' status, rather you would probably have some kind of reversion to a mean, which might be dispreferred by `educated' individuals.
For us, in South Africa, one of the additional problems is to consider whether there are correlations between race and level of education. There have been such correlations historically, which have also led to persistence in inequality of outcomes. However, let us assume that we can overcome the differences by race and have fairly similar distributions across groups. What then? Do we think that diverging, or even persistently separate levels of education is an adequate outcome? If we don't think it legitimate, as I generally don't, What can we do? Where is it legitimate for us to intervene? Is a society in which there is near zero elasticity of parental education to children's education the optimal society?

I am married. I am pursuing my PhD, my wife is currently completing an MA and plans to do a PhD. We fit the 'maritally homogamous' norm. When we have children, I would like to think that they will choose to obtain higher education. This means that my personal incentive is to ensure that there is a non-zero elasticity for my own children. Is it not true to think that educated parents might believe such a thing on aggregate and perpetuate inequality?

Currently have 2 comments:

  1. Interesting. "Marital homogamy" (a term I hadn't heard before), by the way, is a specific instance of (positive) assortative mating, something that goes on in many species. (Positive or negative assortative mating happens by definition whenever mating isn't random, so it's quite a general process).

    There is a bunch of evidence (e.g. here) that humans mate assortatively across a bunch of dimensions, not just education. And it certainly won't be going away...

  2. Yeah, I know the assortative mating idea - I was just trying to give it an 'economic face' for this who know it by its biological names. I agree, it won't go away. I can't think of any legitimate ways to intervene, except to try to get everyone to have a high level of education. This will, of course, take time.