My research has been published in journals such as American Economic Journal: Macroeconomics, Review of Economics and Statistics, Journal of Development Economics, Journal of Health Economics, and the European Journal of Political Research.
Work in Progress
In response to surging immigration pressure in Europe and the United States, Western policymakers advocate foreign aid as a means to fight the `root causes' of irregular migration. This article provides the first global evidence of the effects of aid on migration preferences, migration flows, potential underlying mechanisms, both in the short and longer term. We combine newly geocoded data on World Bank aid project allocation at the subnational level over the period 2008--2019 with exceptionally rich survey data from a sample of almost one million individuals across the entire developing world and data on migration and asylum seeker flows to high-income countries. Employing two distinct causal estimation strategies, we show that in the short term (after the announcement of a World Bank project and within two years after project disbursement), foreign aid improves individual expectations about the future and trust in national institutions in aid-receiving regions, which translate into reduced individual migration preferences and asylum-seeker flows. In the longer term (between three and five years after disbursement), foreign aid fosters improvements in individual welfare through poverty reduction and income increases, resulting in larger regular migration to high-income countries. Our findings show that aid can cause a short-lived reduction in migration aspirations, except in fragile Sub-Saharan African contexts where aid appears ineffective. In contrast, foreign aid enhances individual capabilities over the longer term, contributing to greater regular migration, consistent with the `mobility transition' theory.
In 2015, German Chancellor Angela Merkel decided to allow over a million asylum seekers to cross the border into Germany. One key concern at the time was that her decision would signal an open-door policy to aspiring migrants worldwide - thus, increasing migration to Germany in the long-term. With the continued global rise in forced displacement, Merkel's decision in 2015 provides a unique case study for the fundamental question of whether welcoming migration policies have sustained effects on migration towards destination countries. We analyze an extensive range of data on migration inflows, intentions, and interest between 2000 and 2020. The results reject the 'pull effect' hypothesis while reaffirming states' capacity to adapt to changing contexts and regulate migration.
Forecasting Bilateral Refugee Flows with High-dimensional Data and Machine Learning Techniques.
BSE Working Paper, 1387, joint work with Konstantin Boss, André Gröger, Finja Krüger, Conghan Zheng.
We develop monthly refugee flow forecasting models for 150 origin countries to the EU27, using machine learning and high-dimensional data, including digital trace data from Google Trends. Comparing different models and forecasting horizons and validating them out-of-sample, we find that an ensemble forecast combining Random Forest and Extreme Gradient Boosting algorithms consistently outperforms for forecast horizons between 3 to 12 months. For large refugee flow corridors, this holds in a parsimonious model exclusively based on Google Trends variables, which has the advantage of close-to-real-time availability. We provide practical recommendations about how our approach can enable ahead-of-period refugee forecasting applications.
Sub-Saharan Africa is becoming an increasingly important destination for international migration. The region hosts immigrants from other African countries and from other parts of the world, such as China. Given high poverty levels and weak social security systems in Sub-Saharan Africa, host populations might fear increasing competition for resources and labor, potentially resulting in negative attitudes towards immigrants.
We provide the first systematic study of attitudes towards immigrants in Sub-Saharan African countries that uses a causal framework. Using a survey experiment in Uganda and Senegal, we study both attitudes towards immigrants in general and towards specific immigrant groups. In particular, we focus on Chinese immigrants, whose increasing presence in Africa is seen by many as the most important contemporary geopolitical shift involving the continent.
We find that attitudes towards immigrants are mainly driven by sociotropic cultural and sociotropic economic concerns. Furthermore, immigrants from China are perceived less positively and economically more threatening than immigrants in general.
This paper connects insights from the literature on cosmopolitan values in political science, anxiety in social psychology, and identity economics in a vignette-style experiment. We asked German respondents about their attitudes towards a Syrian refugee, randomizing components of his description (N=662). The main treatment describes the refugee as being aware of and empathetic towards potential Germans' worries about cultural change, costs and violence associated with refugee inflows. This increases reported levels of sympathy and trust substantially, especially for risk averse people. We argue that acknowledging concerns of the host population relieves the tension between an anxious and a cosmopolitan part of peoples' identities. When one aspect of identity is already acknowledged (expressing anxieties) it has less influence on actual behavior (expressing sympathy). In addition, we find that previous contact with foreigners and a higher willingness to take risks are important factors to determine an individual's willingness to interact with refugees.
What Explains People’s Migration Aspirations? Experimental Evidence from Sub-Saharan Africa.
SSRN Working Paper, joint work with Lena Detlefsen, Claas Schneiderheinze.
Migration aspirations lie at the heart of self-selection into migration. In this paper, we study three questions: How do individual, household, origin-country, and destination-country characteristics interact? What factors are most influential? Who wants to leave in what context? We develop a new stylized model which integrates insights from the recently established aspirations-capabilities framework into standard utility maximization. We jointly investigate destination country factors (income and legal status), journey factors (costs and risks involved), and origin country factors (income, economic trends, and quality of public goods) using a conjoint choice experiment with 2708 participants in Uganda and Senegal. Our results show that all these dimensions significantly affect migration decision-making. However, the most important dimensions are the legal status and the risk of dying on the journey. Legal migration opportunities are even more influential for individuals that are content with their income situation at home. In line with the aspirations-capabilities framework, we show that higher life aspirations come with a higher willingness to migrate.
Measuring Chinese Migration in Africa, joint work with Song Yuan and Linda Maokomatanda
A new perspective on the African middle class, joint work with Sékou Metiki
Foreign Exchange Intervention Readiness, joint work with Lukas Menkhoff and Sekou Metiki.
Measuring skill-based wage premia of migration, joint work with Bernd Beber, Jens Ruhose, Yogam Tchokni, Stefan Leopold, and Mame Mor Anta Syll
Published Papers (by topics)
Foreign exchange and FX intervention
Migration decisions and flows
Attitudes toward migration or migration policy
Understanding Differences in Attitudes to Immigration: A Meta-Analysis of Individual-Level Factors.
Journal of Ethnic and Migration Studies, forthcoming, joint work with Lenka Dražanová, Jérôme Gonnot, Finja Krüger.
The European refugee crisis and public support for the externalisation of migration management.
European Journal of Political Resarch 62 (4), 1146-1167, joint work with Alina Vrâncreanu, Elias Dinas, Martin Ruhs.
Effects of migration
Other Publications (Policy Briefs, book chapters, et cetera)
Refugee Protection in the EU: Building Resilience to Geopolitical Conflict.
2022 MEDAM Assessment Report on Asylum and Migration Policies in Europe, joint work with Silvia Carta, Helena Hahn, Paweł Kaczmarczyk, Karolina Łukasiewicz, Mehari Taddele Maru, Marta Pachocka, Matthias Lücke.
Flexible Solidarity: A comprehensive strategy for asylum and immigration in the EU.
2018 MEDAM Assessment Report on Asylum and Migration Policies in Europe, joint work with Esther Ademmer, Mikkel Barslund, David Benček, Mattia Di Salvo, Dominik Groll, Rezart Hoxhaj, Matthias Lücke, Chiara Pizzuti, Merlin Ole Pratsch, Afaf Rahim, Claas Schneiderheinze, Heliodoro Temprano Arroyo, Rainer Thiele, Alessandra Venturini, Carolina Viviana Zuccotti.
Sharing responsibility for refugees and expanding legal immigration.
2017 MEDAM Assessment Report on Asylum and Migration Policies in Europe, joint work with Matthias Lücke, Esther Ademmer, Mehtap Akgüç, Mikkel Barslund, David Benček, Anna Di Bartolomeo, Dominik Groll, Rezart Hoxhaj, Mauro Lanati, Nadzeya Laurentsyeva, Lars Ludolph, Afaf Rahim, Rainer Thiele, Claas Schneiderheinze, Alessandra Venturini.