book review – Didier Ruedin

30 April 2020

Agent-Based Models of Social Life: Fundamentals

Michael Laver has published a short introduction to agent-based models (ABM) for the social sciences. The Cambridge “Fundamentals” series on Quantitative and Computational Methods for the Social Sciences promises to become quite a resource.

While we still don’t have that many texts on ABM in the social sciences, in my view this is an absolute gem. It’s absolutely hands-on from the beginning, using a stock model (Schelling) in NetLogo. Schelling’s model is often cited because it makes apparent that macro outcomes may result from quite different micro-behaviour/intentions. I guess anyone who’s heard of ABM has also heard of Schelling’s model, which makes it quite useful to illustrate many aspects of modelling. In contrast to other texts, this book uses only a single model throughout the book, but we’re exploring this model in some detail… a level of depth we don’t find in other introductory texts, despite the short length of the book.

In fact, in just 130 pages, we get a clear idea not only of the value and potential of ABM, but also the limitations and drawbacks. With the focus on a single model, the author avoids an uncritical “best of” list, and demonstrates how difficult ABM are: the assumptions we include in the model when we program it are put to the test. In this book, it’s not just an abstract discussion, but we get to see — and (hopefully) understand — that design choices like the size of the neighbourhood in the ABM can greatly influence the result we get. In this sense, I really liked how the book introduces the BehaviorSpace of NetLogo very early: ABM are not just little toys, but can be tools to better understand social life. The last section discusses the ever-present trade-off between understanding and predicting, the trade-off between simplicity and ‘realism’.

I’m not sure whether this was intended, but the book seems quite suitable as a introductory course over a semester, or to help self-learners. In either case, I’d supplement it with Gilbert & Troitzsch to better situate ABM within the social sciences more generally, and Railsback & Grimm where programming ABM takes a more central place, not just modifying code to understand the nature of ABM.

Gilbert, N., and K. Troitzsch. 2005. Simulation for the Social Scientist. Maidenhead: Open University Press.

Laver, Michael. 2020. Agent-Based Models of Social Life: Fundamentals. Cambridge University Press. https://doi.org/10.1017/9781108854665.

Railsback, Steven F., and Volker Grimm. 2019. Agent-Based and Individual-Based Modeling: A Practical Introduction. 2nd ed. Princeton: Princeton University Press.

4 January 2020

Academic writing: the one book you really need

There is no shortage of books on academic writing. If you cannot decide where to start, in my view, you should start with “Write No Matter What” by Joli Jensen. Here’s why:

it’s relatively short
it summarizes the best advice out there
it’s realistic

Like other books on academic writing, it starts by addressing common myths about academic writing. I find it painful to see these myths repeated in my own environment. In Jensen’s book, you’ll learn three taming techniques (creating a project box, using a ventilation file, and writing at least 15 minutes every day). So we’re looking at being organized, being realistic (i.e. having room for frustration, writing blocks, etc.), and that important continuing contact with the writing project.

Compared to other similar books I know, I really liked how “Write No Matter What” does not imply that if only you were more disciplined, you’d get all that writing done. No, instead there is an entire section on maintaining momentum, lost trails, and handling revisions and rejections. Getting stalled? There’s an entire chapter on that.

I didn’t enjoy the chapters on writing support that much, but if you’re looking into setting up a campus-wide (or even faculty-wide) writing support, you’ll get plenty of ideas what may or may not work.

Writing style is explicitly not covered, and I think that’s a good thing. Not that books on good writing were redundant — to the contrary! — but this way we get a focused book that can serve everyone from a first-year PhD student to established faculty.

20 April 201820 April 2018

Audit Studies — The Book

There’s a new book edited by S. Michael Gaddis on audit studies. The subtitle promises to go behind the scenes with theory, method, and nuance — and this is what the book provides. As such, the book is a much needed contribution to the literature, where we typically see the results and little how we got there. With (not so) recent concerns around researcher degrees of freedom, the tour behind the scenes offered by the various chapters are an excellent way to make visible and apparent the ‘undisclosed flexibility’ as Simmons et al. called it in 2011. It’s one thing to discuss this in abstract terms, and it’s another thing to sit down with actual research and reflect on the many choices we have as researchers. Indeed, public reflection on research practices may be relatively rare in itself when it comes to quantitative research.

The book comes with a dedicated support webpage: http://auditstudies.com/ (do me the favour to update the “coming soon” banner). On this website, several chapters can be downloaded as pre-prints, though it’s not all the contents if someone is looking for a free book. I hope the authors will make their code available on the website as promised in several places in the book, because this will be another greatly helpful resource for those new to audit studies or looking for new directions.

I greatly enjoyed to read the reflections by other researchers doing audit studies, and would definitely recommend the book to anyone thinking of doing an audit study. At times there were passages that seemed a bit redundant to me, but all the chapters are written in such an accessible way that this didn’t bother me much. Where I think the book falls a bit short is on two fronts. First, it is very US-centric. In itself this is not an issue, but there are several instances where the authors don’t reflect that perhaps in other countries the markets are not organized the same way. In my view, a comparison to other countries and continents would have been fruitful to underline some of these assumptions — I’ve tried to just this on attitudes to immigrants. Second, the book is not a guidebook. I know, it doesn’t claim to be one, but the book asks so many (justified) questions and offers comparatively few concrete guidelines like Vuolo et al. offer it on statistical power. In this sense, the book will stimulate readers to think about their own research design and not provide a template. And this is actually a good thing, because as the chapters make apparent without normally saying so, there is no universal approach that suits different markets in different places and at different times.

So, should you buy the book? Yes if you want to carry out your own audit study, yes if you want to better understand and qualify the results of audit studies, and yes if you’re looking for guidelines — because the book will make you realize that you’re largely on your own. What would probably useful, though, would be a checklist of things to consider, something readers will have to create themselves on the basis of chapters 4 (Joanna Lahey and Ryan Beasley), 5 (Charles Crabtree), and 6 (Mike Vuolo, Christopher Uggen, and Sarah Lageson).

Gaddis, S. Michael, ed. 2018. Audit Studies: Behind the Scenes with Theory, Method, and Nuance. Methodos 14. New York: Springer. https://www.springer.com/cn/book/9783319711522

Ruedin, Didier. 2018. ‘Attitudes to Immigrants in South Africa: Personality and Vulnerability’. Journal of Ethnic and Migration Studies. https://doi.org/10.1080/1369183X.2018.1428086.

Simmons, Joseph P., Leif D. Nelson, and Uri Simonsohn. 2011. ‘False-Positive Psychology: Undisclosed Flexibility in Data Collection and Analysis Allows Presenting Anything as Significant’. Psychological Science 22 (11): 1359–66. https://doi.org/10.1177/0956797611417632.

Vuolo, Mike, Christopher Uggen, and Sarah Lageson. 2016. ‘Statistical Power in Experimental Audit Studies: Cautions and Calculations for Matched Tests With Nominal Outcomes’. Sociological Methods & Research, 1–44. https://doi.org/10.1177/0049124115570066.

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. https://doi.org/10.1080/1369183X.2015.1133279.>/small>

23 March 2017

Review of ‘Politicisation of Migration’ (“SOM Book”)

Almost exactly two years after the publication of The Politicisation of Migration, the book outlining some of they key findings from the SOM project on the politicization of migration, I am happy to announce a review of the book in REFUGE – Canada’s Journal on Refugees. Mark Maguire does a commendable job of synthesizing the book and highlighting potential future areas of work. The book is available from Routledge.