heterogeneity – Didier Ruedin

25 March 2021

New Publication: Decision-Making Under Uncertainty

I’m happy to announce a new publication, coming out of the Swiss Subsaharan African Migration Network. My direct contribution to this thematic issue was the introduction, where I examine common strands of the articles in the issue. As hinted at in the title, the focus is on decision-making under uncertainty — and migration decisions are the example to explore these issues.

When I write about ‘migrants’ here, let’s be clear that there is enormous heterogeneity in this ‘group’: different motivations, different aspirations, different capabilities, and different strategies to deal with the uncertainty inherent in migration decisions.

We do not observe naïve and gullible migrants ignorant of the risks and dangers of irregular migration, nor do we find masses of ‘victims’ tricked by fraudsters and smugglers. Instead, we observe individuals with aspirations, navigating a world characterized by limitations and boundaries. Information is patchy, but this has as much to do with the changing circumstances and opportunities—each risky to some extent. Under these circumstances, migrants show great flexibility to reach their goals, drawing on heuristics and narratives as is common in decision-making under limited information.
p.183

When thinking about migration decisions, it’s better to think about a chain of linked decisions — a chain where circumstances can and do change. In these circumstances, occasionally we also observe what I called “migration velleity” rather than ambition.

Ruedin, Didier. 2021. ‘Decision-Making Under Uncertainty: African Migrants in the Spotlight’. Social Inclusion 9 (1): 182–186. https://doi.org/10.17645/si.v9i1.4076. Open Access.

16 September 2017

Discrimination not declining

A new meta-analysis draws on correspondence tests in the US to show that levels of ethnic discrimination in hiring do not seem to have changed much since 1989. This persistence in racial discrimination is bad news, and indeed Eva Zschirnt and I have shown the same result across OECD countries a year ago. While policies have changed, especially in the European Union, looking at the ‘average’ from correspondence tests suggests that they may not have been effective — and that is bad news.

Correspondence tests are widely accepted as a means to identify the existence of ethnic discrimination in the labour market, and as field experiments they are in a relatively good position to make the causal claims we typically want to make. It turns out that most correspondence tests have not paid sufficient attention to heterogeneity, which — as David Neumark and Judith Rich demonstrate — means that they likely over-estimate the degree of discrimination. Unfortunately, most old studies did not vary the groups in a way that this could be fixed post-hoc. If we throw these out of the meta-analysis, we probably no longer have sufficient studies to make claims about changes over time.

Meta-analyses are no doubt an important tool of science, but there’s always a delicate balance to be struck: are the experiments included really comparable? Here we’re looking at field experiments in different countries, different labour markets, different jobs, and different ethnic groups. We can control for these factors in the meta-analysis, but with the limited number of studies we have, this might not be sufficient to silence critics. With correspondence tests, we only cover entry-level jobs, and despite much more fine-graded studies going into the field recently, we don’t have a tool to really identify why discrimination takes place.

Neumark, David, and Judith Rich. 2016. ‘Do Field Experiments on Labor and Housing Markets Overstate Discrimination? Re-Examination of the Evidence’. NBER Working Papers w22278 (May). http://www.nber.org/papers/w22278.pdf.

Quillian, Lincoln, Devah Pager, Ole Hexel, and Arnfinn H. Midtbøen. 2017. ‘Meta-Analysis of Field Experiments Shows No Change in Racial Discrimination in Hiring over Time’. Proceedings of the National Academy of Sciences, September, 201706255. doi:10.1073/pnas.1706255114.

Zschirnt, Eva, and Didier Ruedin. 2016. ‘Ethnic Discrimination in Hiring Decisions: A Meta-Analysis of Correspondence Tests 1990–2015’. Journal of Ethnic and Migration Studies 42 (7): 1115–34. doi:10.1080/1369183X.2015.1133279.

Image: CC-by CharlotWest