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New Doctoral Training Unit

With the free movement of people within the EU, decreasing transportation and communication costs, global inequality and political instability around the world, more and more individuals have been crossing borders in recent decades, either as permanent or temporary migrants, as daily transnational commuters, or as refugees. These cross-border movements generate important challenges for EU countries in general, and for Luxembourg in particular. In Luxembourg, foreigners account for about 50% of the total population and daily commuters nearly double the size of the national labor force. In this context, ACROSS aims to develop tools to monitor, analyze and improve the understanding of the causes and consequences of these flows – a prerequisite for relevant advice to policy-makers. With financial support of the Luxembourg National Research Fund (FNR's PRIDE funding scheme), ACROSS, gathers economists and geographers from LISER, from the Department of Economics and Finance of the University of Luxembourg, and from the Research Division of STATEC (the National Institute of statistics and economic studies). The three partner institutions aim to create a team of excellence on cross-border mobility, a team where migration and labor market scholars can interact together with data providers, and where new generations of PhD students can benefit from synergies between institutions. Within the consortium, co-promotion will be systematically encouraged to reinforce the links between institutions as well as to train 4 younger researchers in PhD supervision. ACROSS builds on the doctoral education support of the Graduate Studies Program (GraSp) at LISER and of the Doctoral Schools of Economics and Finance (DSEF).
Information provided below:

  • Third round of applications (Spring 2022)
  • Selected PhD candidates (9 / 12 scholarships)
  • List of promoters
  • Research objectives
  • Indicatives topics for PhD dissertations
  • Training and career development

Get together meeting

Kirchberg, December 16, 2022

Third round of applications

New call for applications will be published in the Spring of 2022

Selected candidates

First cohort (out of 116 applications): Oct/Nov2020 - Sep/Oct 2023

Etienne BACHER

from Université Clermont-Auvergne
Immigration, attitudes and politics
Supervised by M. Tenikue and M. Beine

Felix Fabian STIPS

from U. Göttingen & Stellenbosch
Labor market effects of human mobility
Supervised by B. Verheyden and L. Bertinelli


from University of Twente
Human mobility and urban management
Supervised by G. Caruso and P. Picard

Narcisse CHA'NGOM

from UCLouvain & UCA
Geography of brain drain and development
Supervised by F. Docquier and J. Machado

Second cohort (out of 91 applications): Oct/Nov2021 - Sep/Oct 2024


from University of Göttingen
Human mobility and climate change
Supervised by L. Bertinelli and M. Burzynski


from Goethe-University Frankfurt a.M.
Labor migration and development
Supervised by A.. Dupuy and K. Tatsiramos


from University of Heidelberg
Immigration and integration policies
Supervised by C. Gathmann and Skerdi Zanaj


from LMU Munich and UNIBS
Cross-border mobility and policy evaluation
Supervised by M. Beine and F. Docquier

List of promoters

Frédéric Docquier (Coordinator and LISER team leader). He acts as a Research Program Leader on Crossing Borders at LISER and Affilitaed Professor of Economics at the University of Luxembourg. He has published several books and about 100 papers on the measurement, determinants and consequences of international migration in academic journals.
Michel Beine (UniLu team leader) is professor of international Economics at UL since 2005. He holds a PhD from the University of Brussels (1997). His main research interests are in international economics and in particular in the field of international human mobility. He has published significant contributions to the field of international migration. His papers have appeared in renowned journals. He has worked as an external advisor in many institutions such as Industry Canada, the World Bank, the European Commission or the Banque de France.
Luisito Bertinelli is Associate Professor in Economics at UL since 2003. He got a PhD in Economics (UCLouvain, 2003). His present research focuses around environmental and development issues. He has made a number of contributions, notably on the impact of climate factors on economic development. His work has been published in a number of renowned journals.
Michal Burzynski is an economist who specializes in international economics, with a focus on international migration and its impact on labor markets, growth and international trade. He received his PhD from UCLouvain, as a FRS-FNRS research aspirant at IRES (Institut de Recherches Economiques et Sociales).
Geoffrey Caruso holds a Joint Professorship in Urban Analysis and Modelling at UL and LISER since 2017. He is particularly interested in urban forms and urban dynamics and their impact on environmental sustainability and social well-being. As a quantitative geographer, he applies various methods such as spatial statistics, spatial econometrics and geographical Information Systems (GIS) fields. A key specificity of his work relies in bringing more spatial processes and detail in micro-economic based simulation models, through theoretical spatial agent-based models or through more operational land use and transport models.
Arnaud Dupuy is Professor of Economics at UL since 2016. He studied econometrics and applied economics in Grenoble, France and received a Ph.D. from Maastricht University in 2004. Prior to joining UL, he was an assistant professor and senior researcher at the Maastricht University from 2004 to 2012 and the Head of the Labor market department at LISER from 2013 to 2016. His research focuses on matching and hedonic models, performance inequality, micro-foundations of aggregate production functions and sports economics.

Christina Gathmann has been a professor of labor economics and political economy at the University of Heidelberg since 2011. She is the designated Head of the Labor Department at LISER and expects to take up her position at LISER starting in 2020. Christina holds a PhD from the University of Chicago. Her main research interests are in labor economics and public economics with a strong interest in interregional and international immigration flows and their economic, social and political consequences.
Joël Machado completed his PhD in Economics in October 2014 at UCLouvain. Before joining LISER as a researcher, he was a FNR-AFR Postdoctoral researcher at CREA, UL, from July 2015 to June 2017. His work uses quantitative and empirical methods to study the causes and consequences of migration as well as the impact of policies on the management of migrant flows and the integration of immigrants in the destination countries.
Chiara Peroni (STATEC team leader) is the head of STATEC Research Division. Chiara holds a PhD in Economics from the University of York. She joined STATEC as a senior researcher in April 2011. Chiara is an econometrician with a background in macroeconomic analysis and financial econometrics. She is interested in the application of non-parametric methods to measure productivity and efficiency, and to study policy issues, such as environmental degradation and quality of life. She is engaged in analyzing how welfare is linked to economic outcomes and entrepreneurship.
Pierre Picard is Professor at UL since 2008, after serving as a Senior Lecturer at the University of Manchester (UK) (1999-2008). He has expertise in regional, international and urban economics and economic geography and focuses on the urban location of business and residents and on the principle of free mobility of workers between countries. He was the head the Doctoral School in Economics and Finance up to September 2019.
Cesare Riillo is a researcher at STATEC Research. His research interests include innovation, entrepreneurship, standardization economics, and survey methodology. Cesare, who participates in the scientific board of GEM, is responsible for the Luxembourg’s Global Entrepreneurship Monitor project. He holds a PhD in Human, Territory and Society Sciences obtained from the University of Trieste, Italy.
Konstantinos Tatsiramos holds a Joint Professorship in Labor Economics at UL and LISER. He received a PhD in Economics from the European University Institute in Florence. His main research interests lie in labor economics and applied micro-econometrics, with particular emphasis on labor market institutions, unemployment dynamics, mobility and inequality. In 2011, he has been acclaimed as Leading Book Series Editors in the Emerald Literati Network 2011 Awards for Excellence.
Michel Tenikue is a research at LISER. He holds a PhD in Economics from the University of Namur (Belgium). His is specialized in Development Economics with an emphasis on economics of education and demographic economics. He has designed and implemented impact studies in sub-Saharan Africa and in India. His recent research investigates consequences of population dynamics on (income) inequality dynamics. He has ongoing research project on socio-economic integration of migrants in developed countries.
Bertrand Verheyden is a researcher and formerly Head of the Labor Market Department at LISER. He received his PhD in Economics at the University of Namur in May 2008. He is a public economist interested in the fields of Labor, Migration and Education. He produces normative analyses on important societal challenges such as the optimal provision of childcare and education, the international mobility of human capital and migrants’ integration.
Skerdilajda Zanaj is an Associate Professor at UL since May 2011. She graduated in Economics Science at the University of Lecce and then completed her PhD in Economics at CORE in 2008 (UCLouvain in cotutelle with the Università degli Studi di Siena). Skerdilajda Zanaj is interested in topics linking the fields of public economics, international economics and industrial organization. Her contributions cover a vast span of areas in economics such as tax competition, migration, nationalism, intergenerational transmission of preferences.

Research objectives - Extend the knowledge base and inform evidence-based governance of cross-border flows.

Determinants of cross-border mobility

In most countries, international migration is the most debated facet of human mobility. The number of asylum applications lodged in 2015 in EU Member States exceeded 1.3 million. This placed migration policy in the forefront of the global policy debate, as is often the case after each immigration peak. However, the concern over migration policy can be seen as the by-product of a long-lasting process of increasing immigration that has been occurring for the last 50 years or so. In the US and in the EU15, the stock of legal international immigrants has been multiplied by 4 since 1960. In the EU15, the stock of immigrants originating from developing countries has been multiplied by 8.7 since 1960, and by 2.3 since 1990 (Ozden et al. 2011).
Qualitatively, the underlying global root drivers of these trends are known – demographic imbalances, economic inequality, increased globalization, political instability, climate change, etc. – and the role of migrant networks in generating dynamic multiplier effects is well understood (Beine et al. 2011). Digital transformation in developed economies has also increased the demand for highly skilled workers. In some areas, such as Luxembourg, the local supply of such workers is insufficient. Only a few studies have empirically investigated the long-run causes of migration in a global setting (see Hatton and Williamson 1994, 2003, 2005; Dao et al. 2017). Hence, little is known about the relative contribution of each root cause of migration in explaining the long-run trends in the size and structure of migration. In addition, International migration laws/policies have been rarely accounted for in empirical studies, due to the difficulty to classify and code them.
We plan to develop new approaches to explain long-term trends in international migration and anticipate future pressures. We will extend existing quantitative methodologies (e.g., Lutz et al. 2014) to dissect the inter-relationships between migration, population growth, education decisions and economic development. To shed light on the effectiveness, legal consistency and coherence of policy reforms, ACROSS could make use of data on immigration policy in the context of the IMPALA project conducted a few years ago in Luxembourg (Beine and Souy 2016). We propose to carry out empirical analysis of the long-term determinants of migration. For example, concerning highly skilled workers, the role of push and pull factors can be addressed by using original data on job vacancies in the EU on the one hand, and microdata on EU Blue Card candidates (i.e., potential migrants) on the other hand. Given the complex interdependencies between migration, population and income, we will also develop multi-country, micro-founded general equilibrium models with overlapping generations of individuals to understand the forces at work (see Delogu et al. 2018; Docquier and Machado 2018; Burzynski et al. 2019a,b).
Secondly, existing statistics emphasize the nonpermanent nature of many migration decisions. In a recent report, the OECD (2008) estimates that 20 to 50% of immigrants leave the host country within the first five years after arrival, depending on the countries and time periods considered. Dustmann and Görlach (2016) estimate that immigrant out-migration rates are substantial and larger from European destination countries than from the US, Canada or Australia. This highlights the rising temporary nature of European human mobility, which raises new challenges in terms of integration policies, social cohesion, taxation, housing, etc. We plan to shed light on the determinants of migration temporariness and its economic and social implications (e.g., Delpierre and Verheyden 2014a). This requires conducting new empirical studies focusing on the determinants of temporariness, and developing new models that jointly endogenize migrants’ duration of stay and the consequences for the host countries.
In many countries, internal/interregional migration is an even more sizeable phenomenon. Bell et al. (2015) find that internal migration intensity is 60 times more important than international migration worldwide. Official cross-country databases on infra-national mobility are imprecise, and are difficult to reconcile with coarse international flow data. With a few exceptions (Beine and Coulombe 2018, Burzynski et al. 2019a, 2019b), little is known about the interplay between internal and international migrations. We plan to go beyond the state of the art in combining traditional and new sources of data. For instance, researchers have relied on Big Data using cell phone data – see for instance Beine et al. (2019) in the case of refugees in Turkey. Other approaches rely on worldwide opinion surveys on migration intentions and geo-referenced data on population changes. Gridded data sources are available and allow researchers to better connect spatial shocks and mobility decisions (Rango and Laczko, 2017; Blumenstock et al. 2015). These new data sources can potentially revolutionize the understanding of the drivers of migration flows. They also raise important challenges in terms of storage, analysis, estimation, visualization, and information privacy; this requires developing new methodologies for processing and analyzing them (e.g., data mining, machine learning algorithms). We ambition that the exploratory analyses of Big Data conducted in this DTU will serve as a foundation for a larger data infrastructure project focusing on the measurement of human mobility in virtually continuous time and space.
Linked to internal movements, daily cross-border commuter flows have a strong incidence on the economy of receiving and sending countries and regions. In general, immigration and cross-border commuting increase the process of urbanization in the receiving country (Bertinelli and Black, 2004). This is particularly the case in Luxembourg or in the Alpine region (e.g., Geneva, Basel, Salzburg, Monaco, Trieste, Milan). In 2018, 191,998 of Luxembourg employees were commuting from their country of residence, which ranks Luxembourg as the third country in Europe hiring most cross-border workers living in a different country in absolute numbers, behind Germany and Switzerland (EC, 2019)! The importance of these flows raises the question of their long-run sustainability (Picard and Worrall 2018). Again, little is known about the interplay between commuter flows and residential mobility. We propose to develop new location choice models that jointly endogenize decisions about place of work and place of residence, especially in case where there is important wage and job-opportunity differentials on both sides of the border. Analytical and simulation models can help understanding the effect of non-integrated land use or transport policies on the spatial segmentation of land/housing markets, over/sub densification at borders and “elastic migrants” behavior (moving across borders because of housing markets, but keeping all daily activities on the original side). On the applied side, we plan to explore the possibility to construct two-dimensional nested logit models for work and residence, and estimate (or calibrate) them using data on commuters and migrants.

Consequences of cross-border mobility

Many models have been constructed to investigate the main transmission mechanisms through which international migration affects welfare and income in the host country (typically, the labor market, fiscal, price, and productivity channels), and to account for interactions between them. Worries are also driven by non-economic factors such as an adverse effect on social cohesion, national identity, crime, terrorism, etc. Quantitatively, new approaches are needed to compare the effect of different forms of mobility.
The labor market effects of immigration have been studied in a large number of studies. In this literature, the concrete formalization of the labor market and the identification technique vary drastically across studies. Yet, there is growing consensus on the fact that immigration induces small effects on natives’ average wage but larger redistributive effects between broad groups of workers. It remains difficult, however, to precisely identify who wins and who loses within these broad groups, as well as the extent of the gains/losses. Going beyond the state-of-the-art requires modelling wage responses by narrow segment of the wage distribution (e.g., by occupation or by task) and mobility of natives and immigrants along that distribution (e.g., occupational choices or task specialization).
In general, investigating the effects of cross-border mobility on growth and income distribution requires new empirical studies accounting for mobility-related changes in human capital accumulation and in cultural diversity; Human capital and diversity are key drivers of innovations and directed technical changes; Skill-biased technical changes are influenced by research-and-development policies and by firms’ responses to the changing environment. Little is known on firms’ responses to an increase in the share of cross-border workers in the economy. By shifting labor supply, immigrants and commuters affect the skill composition of the labor force, which may change the skill mix demanded by firms. It is vital for Luxembourg to understand the role of cross-border mobility on the speed and nature of technical progress, and to identify the needs for a successful transition towards a knowledge-based economy.
Another consequence of cross-border inflows and immigration is the global effect on entrepreneurship and firm creation. A growing stream of studies focuses on immigrant entrepreneurs’ contributions to the economy looking at entrepreneurship differences across groups as well as differences in entrepreneurial success. Immigrants are widely perceived as being highly entrepreneurial and important for innovation. In that respect, three types of investigations will be carried out. Firstly, what are the differentiated effects of cross-border workers and immigrants on entrepreneurship? What are the factors explaining these differences? Secondly, how do migrant-founded start-ups impact native-founded companies? Should we expect a negative opportunity stealing/crowding out effect or a positive spillovers due to enlarging the entrepreneurial ecosystem and increasing economic activity? Thirdly, entrepreneurs in the receiving countries are likely to have built on previous experience at origin. Therefore, estimating rate of persistence of entrepreneurship across borders would be an important topic of study.
It is also important to gain understanding of the link between cross-border mobility and political or labor market institutions. The literature on immigration, natives’ attitude and political preferences has grown rapidly for the last ten years. Focusing on a specific country/city and on the votes for a specific populist party, recent papers uncover a causal effect of immigration on the vote shares for right-wing parties many countries. This result is found in many countriesThe fear of adverse labor market or fiscal effects of immigration are usually perceived as a direct cause of populist votes. These economic effects are governed by the skill structure of the immigrant population. In general, larger regional inflows of highly educated immigrants are associated with a lower support for populist/nationalistic parties, while inflows of less educated immigrants boost voting for populist parties. This strand of literature deserves being extended into three directions. Firstly, we plan to investigate whether cross-border commuter flows influence political preferences with the same intensity and in the same direction as migration flows do. Considering the case of Luxembourg, we can test whether local exposures to immigrants and commuters cause hostile or positive reactions from the natives. Secondly, almost nothing is known about the reverse impact of populism on the size and structure of immigration. We may fear that the rise of populism influences the negative selection of migrants and increases cultural polarization in the host-country society, thereby reinforcing cleavages and inducing vicious circles. Finally, little is known about the impact of cross-border workers on labor market institutions and regulations. Consider again the case of Luxembourg. The employment share of cross-borders has increased dramatically from 10% in the mid-1980s to about 50% in 2019. As a result, the bargaining power of cross-border workers has increased. Yet, cross-border workers’ objectives are not necessarily aligned with those of resident workers. The sharp increase in the share of cross-border workers together with their differential objectives compared to residents might induce significant impact on labor market regulations.
A recent strand of the literature has revealed that large migration flows can create important evolution of local social norms at destination for instance show that, following the collapse of the Berlin Wall, the large migration inflow of East Germans has significantly affected cultural norms in the West: Western women started working more hours both on the labor market and within the household following the inflow of, more gender-egalitarian workers from the East. We plan to contribute to this incipient literature by investigating the extent to which social norms are transmitted through cross-border movements within the Greater Region.
All growing urban regions face important challenges in terms of land use, especially to reduce excessive sprawl and transportation, especially with the aim of increasing the efficiency and use of public transportation and reducing congestion. When a functional region actually spans over a border, further spatial heterogeneity is added, which makes the use and implementation of planning instruments (such as distance-based taxes or urban growth boundaries) more difficult. The management of traffic and congestion, and pressures on the housing markets are often reported as main challenges by local planning authorities in many cross-border metropolitan regions. Surprisingly though, the political focus is set on facilitating flows and improving accessibility, little attention is actually given on the structural causes, negative externalities and other feedback of cross-border flows. Comprehensive models are much in need here, where land/housing and labor market interacts given the constraints (or changes in) of a transportation system.

Indicative topics for PhD dissertations:

Although some flexibility must be given to supervisors and PhD students in defining the research agenda, we propose here a list of indicative topics for PhD dissertations:
  • Interplay between internal and international migration: use of traditional and innovative data sources for estimating internal and international migration responses to shocks (M. Beine, L. Bertinelli, J. Machado).
  • Mid- and long-term projections of international/internal migration: building OLG models of the world economy to analyze historical mobility trends and predict future migration flows (M. Burzynski, F. Docquier, M. Tenikue).
  • Joint analysis of commuting and residential mobility: development of bi-dimensional location models with endogenous place of work and place of residence (M. Beine, L. Bertinelli, G. Caruso, P. Picard).
  • Challenges raised by temporariness of migration (J. Machado, B. Verheyden, M. Tenikue).
  • Cross-border mobility and entrepreneurship: links between immigrant- and native-founded companies, cross-border transmission of entrepreneurial skills (C. Peroni, C. Riillo, K. Tatsiramos, B. Verheyden)
  • Economic, social and political integration of immigrants: effectiveness and coherence of integration policies (C. Gathmann, M. Tenikue, B. Verheyden, S. Zanaj).
  • Impact of cross-border labor mobility on the wage distribution: development of new model endogenizing occupational choices and wage disparities (M. Burzynski, A. Dupuy, C. Gathmann, K. Tatsiramos).
  • Effect of cross-border mobility on social norms and happiness (C. Peroni, C. Riillo, S. Zanaj).
  • Effect of cross-border mobility on public and private institutions: effect of commuting and residential mobility on voting; effect on labor market institutions (F. Docquier, A. Dupuy, S. Zanaj).
  • Effect of mobility-driven changes in human capital and cultural diversity on the magnitude and nature of technical progress; optimal structure of cross-border movements to make Europe and Luxembourg a dynamic and competitive knowledge-based economy (C. Gathmann, C. Peroni, K. Tatsiramos, B. Verheyden)
  • Effect of daily cross-border movements on congestion and traffic (G. Caruso, P. Picard)
  • High-skilled immigration policies in the knowledge based economy; What explains differences in selective policies between European member states? What explains differences in the usage of the Blue Card and in attractiveness of European countries? Is cooperation desirable? (J. Machado, B. Verheyden)

Training and Career Development

LISER will coordinate the DTU which is linked to its Graduate Studies Program (GraSP) and embedded into the Doctoral School in Economics and Finance (DSEF) at UL. GrasSP and DSEF currently host 21 and 30 PhD candidates in Economics, respectively.
The partners have a track record of sharing their supply of doctoral courses through various channels: training activities co-organized by LISER and Unilu have been regularly proposed. Both institutions also proposed joint LISER/DSEF PhD Workshops (the first was organized as early as September 2015). Very recently, LISER and DSEF have initiated a series of doctoral lectures on cross-border labor mobility involving the participation of renowned scholars such as Hillel Rapoport, Christina Gathmann, Simone Bertoli, Giovanni Fachhini, Klaus Desmet, Giovanni Peri, etc.
All PhD students will have to participate in both LISER and DSEF training activities and seminars. DSEF offers scientific courses dedicated to acquiring knowledge in common research theory and methods in Economics and Finance. The School also offers “field” transferable skill courses in which PhD students acquire skills transferrable within their own field.
In addition, PhD students will be asked to take part in specific activities related to the topic of this DTU. The table below describes the core training programme offered by ACROSS. It comprises general PhD courses, specific training courses on cross-border mobility, a series of doctoral lectures given by international renowned scholars in the field, three offsite retreats offered to PhD students and supervisors on data management, machine learning and policy evaluation, responding to the ongoing trends in economic research, and job market sessions.
The offsite learning events constitute a unique opportunity to develop and initiate joint publications among supervisors and PhDs of the DTU. On top of that, ACROSS students are invited to present in PhD workhops organized twice a year by the DSEF (Jamboree PhD workshops). They will be invited to participate to research seminars regularly organized by STATEC on the DTU-related topics.