Labour, Migration and Marriage Through the Microscope of Micro-Data

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Professor Dorrit Posel with the College of
Humanities Deputy Vice-Chancellor, Professor
Cheryl Potgieter.

Professor Dorrit (Dori) Posel of the School of Built Environment and Development Studies (BEDS) recently gave her Inaugural Lecture at the Howard College Theatre on “Labour, Migration and Marriage through the Microscope of Micro-data”.

‘It has been 20 years since the first nationally representative household survey was conducted in South Africa. There are now more than 50 micro-datasets available which provide detailed information on the characteristics of individuals in South Africa, the households in which they live, the work that they do, and the income that they receive and spend,’ said Posel.

In her Lecture, Posel explored how the availability and richness of micro-data (data about individual units, and typically individuals) have changed the scope of economics in South Africa, drawing examples from her own research on labour markets, migration and marriage.

National micro-data are used to describe and analyse the socio-economic and demographic characteristics and the behaviour of people living in South Africa. The data are also used to explore how characteristics and behaviour in South Africa have changed over time – for example, in response to changes in macro-economic conditions, or in economic and social policy.

‘The richness of the micro-data which are collected has also made it possible to explore questions not typically associated with economics. In turn, economics has become far more inter-disciplinary, drawing from and contributing to, a range of other disciplines, including development studies, demography, evolutionary biology, sociology, psychology, geography, politics, history, anthropology and linguistics.’

As examples, Posel explained that in her own research, she had used micro-data to test for evidence of kin-based altruism, to understand differences in levels of happiness, and happiness gaps within couples specifically, and to explore racial differences in the willingness to trust in South Africa.

One of the areas explored in her Lecture that garnered much interest from the audience, was the interaction between the labour market and the marriage market, where she explored the male marital earnings premium as an example.

‘A very well-documented finding from a wide range of countries is that men who are married earn substantially more than men who are otherwise identical but are not married. There are two main explanations for why this premium should exist. The first is the “productivity hypothesis”, which suggests that marriage makes men more productive, and because they are more productive, married men earn more.

‘The alternative explanation, known as the “selection hypothesis”, reverses the causality: it is not that marriage makes men earn more; rather it’s that men who earn more are more likely to marry – which is why we observe married men as having higher earnings on average than never-married men.’

Posel’s research revealed evidence of a sizeable marital earnings premium in South Africa particularly among African men, a premium which her research suggests derives primarily from the selection of higher-earning men into marriage.

Posel’s research on labour, migration and marriage using micro-data has resulted in many collaborative research projects over the years. She concluded her Lecture, noting that:

Since 1993, with the introduction of the first nationally representative household survey, the scope of economics in South Africa has broadened considerably, and economists have travelled along a dynamic, diverse and often also steep road.

‘I have found this journey to be highly stimulating, but it would not have been possible, and certainly not as rewarding without the support, collegiality and input from the many colleagues and students with whom I have worked.’