Selected Publications

In this article, I investigate preschool children’s participation in organised activities. Current political and academic debates consider informal education as a prime vehicle for potentially diminishing social class inequalities in educational outcomes before school entry. However, studies point to unequal participation rates between social classes, which means the activities might actually aggravate existing disparities. Various explanations have been offered for this social class gap. Some scholars argue that material resources play a pivotal role, while others say that culture is the decisive factor. This study uses the kindergarten cohort of the German National Educational Panel Study (NEPS) to test how far these two dimensions contribute to social class differences in preschool children’s participation in organised activities. My analysis shows that both dimensions are important determinants of children’s participation in organised activities. However, occupational characteristics also have a considerable effect, which suggests shortcomings in the current scholarly discussion.
In EECERJ, 2018.

This explorative article contributes to research on models of “good parenting” by analyzing whether current demands of politics, science and advice literature are discussed in a large German parenting online forum. The data consists of 58,240 user submissions to a digital discussion board. Using this digital data, it can not only be analyzed which topics users discuss but also how they negotiate them. With “topic modeling”, an innovative approach from the computational social sciences (CSS), is combined with qualitative content analysis. The article shows that expert knowledge is picked up by users to justify and reflect on their childrearing practices. By and large, parents refer to expert knowledge in a positive manner, however, some authors are viewed rather critically.
In Journal of Family Research, 2018.

Visa policies today are a central instrument for filtering wanted and unwanted types of travellers, leading to a hierarchy of mobility rights. While there is evidence of a “global mobility divide”, we still know little about the role of regional integration when it comes to the distribution of mobility rights and the (re)structuring of mobility spaces. Against this background, the article examines the structure of visa relations in different bodies of regional integration (EU, MERCOSUR, ASEAN, ECOWAS, EAC, NAFTA, SADC and SICA). The article compares visa policies in the member states of these institutions in 1969 and 2010 from a social network perspective. While one would generally expect each institution’s member states to become more similar with regard to both internal and external mobility regulations, we find that not all regional clusters align their visa policies. Potential explanations for this state of affairs are investigated.
In International Migration, 2016.

Recent Publications

. Regional Mobility Spaces? Visa Waiver Policies and Regional Integration. In International Migration, 2016.


. Circumventing deadlock through venue-shopping: why there is more than just talk in US immigration politics in times of economic crisis. In Journal of Ethnic and Migration Studies, 2016.


. The Global Mobility Divide: How Visa Policies Have Evolved over Time. In Journal of Ethnic and Migration Studies, 2015.


Recent Posts

Recently, I was invited by Prof. Dr. Henning Lohmann to talk about “Webscraping with R” at the Department of Socioeconomics (University of Hamburg, UHH). Among other things, I discussed the perils and promises of digital research, the infrastructure of the web, and how to implement a webscraping project using R. The (German) slides are available below. After the presentation, the participants and I dug into several examples, which I also made available on my GitHub.


Admittedly, the post at hand emerged from a very plain issue. In Germany, statutory health insurances charge a supplemental premium which differs between the respective providers. Recently, my current provider increased its’ premium and I was confronted with the option to switch to a potentially less expensive one. To make an informed decision, I tried to compare the supplemental premia across providers available at my place of residence (Berlin). Data on the respective premia are available at the website of the “National Association of Statutory Health Insurance Funds”.


Global Visa Policies Recently, I started a new position in a project that aims at developing a typology of border walls at a global scale. Against the backdrop of globalization literature of the 1990s, it has been shown that instead of world that is increasingly ‘borderless’ (Ohmae 1990) we actually observe more and more fortification (Hassner & Wittenberg 2015). While I will certainly write more about this project once it matures, this post features related data that I collected with colleagues at the University of Bremen: The Visa Network Data.



Borders of the World

The research project ‘Borders of the World: Processes of De- and Rebordering in a Global Perspective’ (CRC 1265)

PhD thesis

My PhD thesis on normative ideals of ‘good parenting’.


Currently, I do not have teaching obligations. However, I regularly organize workshops on webscraping, text mining and visualization with R.

For an overview of my teaching portfolio see my homepage at the chair of macrosociology link.