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

Here's the link to my Google Scholar site.

Work in Progress

The Effect of Foreign Aid on Migration: Global Evidence from World Bank Projects.

Kiel Working Paper, joint work with Andreas Fuchs, André Groeger, and Lukas Wellner

We have written a non-technical summary with policy implications: English summary     Deutsche Zusammenfassung 

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.

Forecasting Bilateral Asylum Seeker Flows with High-dimensional Data and Machine Learning Techniques.
BSE Working Paper, 1387, joint work with Konstantin Boss, André Gröger, Finja Krüger, Conghan Zheng.

Conditionally accepted at the Journal of Economic Geography

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.

What Drives Attitudes Towards Immigrants in Sub-Saharan Africa? Evidence from Uganda and Senegal
IZA Discussion Paper 16734, joint work with Malte Becker, Finja Krüger.
Under revision

We explore whether attitudes toward immigration and their determinants known from well-studied high-income countries also hold in so far understudied low-income settings where the economic, societal, and geopolitical circumstances differ markedly. Using a causal framework based on experimental and survey data in Uganda and Senegal, we extend the literature by introducing a new concept - power concerns - to test whether perceptions of foreign influence in business and politics affect attitudes toward immigrants. Furthermore, we provide evidence of the perceptions of Chinese immigrants in Africa, whose increasing presence is highly controversial and politicized.

Conflicting Identities: Cosmopolitan or Anxious? Appreciating Concerns of Host Country Population Improves Attitudes Towards Immigrants.
outdated version: IZA Discussion Paper 12630, joint work with Philipp Wichardt. 

Accepted for publication at Social Forces

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.
Under revision

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.

Preparing for FXI
SSRN Working Paper, joint work with Lukas Menkhoff and Sekou Metiki.

 The use of FX intervention (FXI) is preceded by policymakers’ institutional decisions. We show that FXI activity increases with the choice of more rigid exchange rate regimes, larger official reserve assets (relative to GDP), and reserves held in a form easing their use for FXI, which we demonstrate by developing an FXI “readiness” index. These institutional decisions well explain but can hardly predict FXI. Despite their costs, our findings show that policymakers have expanded FXI preparations over the last two decades and that less democratic countries tend to be more prepared. 

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

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)

If replication material is not linked directly with the publication below, for example, because the data are proprietary, please contact me.

Foreign exchange and FX intervention

Foreign Exchange Intervention: A New Database.
IMF Economic Review. 10.1057/s41308-022-00190-8. joint work with Marcel Fratzscher, Lukas Menkhoff, Lucio Sarno, Maik Schmeling.
Publication Open Access   Dataset 

The Dynamic Impact of FX Interventions on Financial Markets.
The Review of Economics and Statistics, 103 (5), 939–953, joint work with Lukas Menkhoff, Malte Rieth.
Publication Open Access

When is Foreign Exchange Intervention Effective? Evidence from 33 Countries.
American Economic Journal: Macroeconomics 11 (1), 132-156, joint work with Marcel Fratscher, Oliver Gloede, Lukas Menkhoff, Lucio Sarno.
Publication Author's copy   

Migration decisions and flows

Does Welcoming Refugees Attract more Migrants? The Myth of the 'Merkel Effect'.
joint work with Jasper Tjaden.
Published online first by European Journal of Political Research

Open Access      Replication Material 

Searching for a Better Life: Predicting International Migration with Online Search Keywords.
Journal of Development Economics 142,  joint work with  Marcus Böhme, André Gröger.
Publication Open Access Replication Material 

Siblings' Interaction in Migration Decisions: Who Provides for the Elderly Left Behind.
Journal of Population Economics 28, 593-629.
Publication Author's copy

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 50:2, 317-340, joint work with Lenka Dražanová, Jérôme Gonnot, Finja Krüger. 

Open Access Publication

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.

Open Access Publication

A Need for Control? Political Trust and Public Preferences For Asylum and Refugee Policy.
European Political Science Review, 15 (3), 427-443, joint work with Anne-Marie Jeannett, Martin Ruhs.
Publication Open Access

What Asylum and Refugee Policies Do Europeans Want?  Evidence  from a Cross-National Conjoint Experiment.
European Union Politics 22:3, 353-376, joint work with Martin Ruhs, Anne-Marie Jeannet.
Publication Open Access

Much Ado about Nothing? The (non-) Politicisation of the European Union in Social Media Debates on Migration.
European Union Politics 20(2), 305-327, joint work with Esther Ademmer, Anna Leupold.
Publication Author's copy

Effects of migration

Can Parental Migration Reduce Petty Corruption in Education?
The World Bank Economic Review 32(1), 109-126, joint work withLisa Sofie Höckel, Manuel Santos Silva.
Publication Open Access

Alone but better off? Adult child migration and health of elderly parents in Moldova.
Journal of Health Economics 29, 211-227, joint work with Marcus Böhme, Ruth Persian.
Publication Open Access

The Returns to Occupational Foreign Language Use: Evidence from Germany.
Labour Economics 32, 86-98.
Publication Open Access

Heterogeneous Immigrants, Exports and Foreign Direct Investment: The Role of Language Skills.
The World Economy 41(6), 1529-1548, joint work with Matthias Lücke.
Publication Open Access

Analysis and Forecasts of Migration to Germany.
Kieler Beiträge zur Wirtschaftspolitik 34, joint work with Nils Jannsen, Dominik Groll, René Kalweit, Bernard Boockmann.

Other topics

Long-Run Impacts of the Conflict in Ukraine on Food Security in Africa.
African Development Review, joint work with Lavina Balma, Sebastian Jävervall, Hendrik Mahlkow, Adamon Mukasa, Andinet Woldemichael.

 Open Access Publication
Early version of analysis (March 2022): Kiel Policy Brief, Ukraine Special 1

Household Interview Duration Analysis in CAPI Survey Management.
Field Methods 26(4), 390-405, joint work with Marcus Böhme.
Publication Open Access

Other Publications (Policy Briefs, book chapters, et cetera)

Joint Futures: Ideas for Germany’s Africa Policy - Ideen für die deutsche Afrikapolitik .
Megatrends Working Paper 14, collection of commentaries by 50+ authors

The Russia-Ukraine War’s Shockwaves in Africa. A Zeitenwende for German Africa Policy?
Megatrends Working Paper, joint work with Christine Hackenesch, Wolfram Lacher (eds.), Fahd Azaroual, Oumayma Bourhriba, Cynthia Kamwengo, Stephan Klingebiel, Melanie Müller, Bettina Rudloff, Meike Schulze, Denis M. Tull, Cobus van Staden

Flüchtlingsschutz als internationales öffentliches Gut organisieren
Ifo Schnelldienst, 10/2023, joint work with Matthias Lücke.

Research on Public Attitudes to Migration: What, Where, and Who?
OPAM Project - Data visualization and analysis, joint work with Lenka Dražanová, Jérôme Gonnot, Finja Krüger.

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.

The Potential of Big Data for Macroeconomic Analysis.
Kieler Beiträge zur Wirtschaftspolitik 32, joint work with Martin Ademmer, Joscha Beckmann, Eckhardt Bode, Jens Boysen-Hogrefe, Manuel Funke, Philipp Hauber, Julian Hinz, Nils Jannsen, Stefan Kooths, Mareike Söder, Vincent Stamer, Ulrich Stolzenburg.

Systematic Intervention and Currency Risk Premia.
SSRN Working Paper, joint work with Marcel Fratzscher, Maik Schmeling, Lukas Menkhoff. Eternal working paper

Emerging from Covid-19: Scenarios for Africa.
Kieler Beiträge zur Wirtschaftspolitik 26, joint work with Kacana Khadjavi, Rainer Thiele.

Student Performance and Attendance in Moldova from a Socio-economic perspective.
World Bank Economic Note, joint work Anna Olefir, Tom Coupe, Anatol Gremalschi.

Conservative Innovators.
Development and Cooperation - Comment, joint work Linda Kleemann, Lukas Borkowski.

Welfare Effects of Regular and Irregular Migration.
Forced Displacement and Migration, 231-244, joint work with David Benček, Matthias Lücke, Claas Schneiderheinze.

Comforting Immigration Critics? Public Opinion toward Development Aid as a Tool to Reduce Refugee Inflows to Germany.
MEDAM Policy Brief, joint work with Jens Eger, David Hudson, Sebastian Schneider, Jennifer van Heerde-Hudson.

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.

Europeans are More Accepting of Immigrants Today than 15 Years Ago.
MEDAM Policy Brief, joint work with Esther Ademmer.

The Making of a New Cleavage? Evidence from Social Media Debates About Migration.
Kiel Working Papers, joint work with Esther Ademmer. Eternal working paper

Wie kann eine gesamtwirtschaftlich erfolgreiche Integration der Flüchtlinge gelingen?
Abschlussbericht an das Bundesministerium für Wirtschaft und Energie, joint work with Bernhard Boockmann, Matthias Lücke, Henry Puhe, Heidi Hirschfeld, Günther Klee, Christiane Knirsch, Tobias Scheu, Jochen Späth.

30 Years of Schengen: Internal Blessing, External Curse?
Kiel Policy Brief 88, joint work with Esther Ademmer, Toman Barsbai, Matthias Lücke.