Migration accounting model¶
Root Drivers of Internal Migration¶
Socio-demographic disparities between countries are instrumental in explaining past migration trends (1970-2020).
Dao, T.H. & F. Docquier & M. Maurel & P. Schaus (2018). Global migration in the 20th and 21st centuries: the unstoppable force of demography. Review of World Economics, 157, 417-449.
This paper sheds light on the global migration patterns of the past 40 years, and produces migration projections for the 21st century. To do this, we build a simple model of the world economy, and we parameterize it to match the economic and socio-demographic characteristics of the world in the year 2010. We conduct backcasting and nowcasting exercises, which demonstrate that our model fits very well the past and ongoing trends in international migration, and that historical trends were mostly governed by demographic changes. Then, we describe a set of migration projections for the 21st century. In line with the backcasts, our world migration prospects are mainly governed by socio-demographic changes. Using immigration restrictions or development policies to curb these pressures requires sealing borders or triggering unprecedented economic takeoffs in migrants’ countries of origin. Increasing migration is thus a likely phenomenon for the 21st century.
Docquier, F. (2018). Long-term trends in international migration: lessons from a macroeconomic model. Economics and Business Review 4(18-1), 3-15.
In this paper I develop a stylized model of the world economy and use it to explain the long-run trends in international migration. The model very well fits the trends of the last 40 years which are mainly governed by the evolution of population disparities between industrialized and developing countries. Then I provide migration projections for the 21st century and show that future migration is also governed by socio-demographic changes. I predict a robust increase in immigration pressures from sub-Saharan Africa and MENA countries to European countries.
International migration is a selective process as the propensity to emigrate increases with education. Selection decreases with development, but the brain drain often turns into a brain gain in the poorest countries of the world.
Docquier, F. & S. Veljanoska (2020). Is emigration harmful to those left behind? Annual Reviews of Resource Economics, 12, 367-388.
From the perspective of sending countries, international migrants are positively selected in terms of schooling, particularly in low-income countries. While emigration affects human capital accumulation, it also induces positive spin-offs in the form of remittances, incentives to acquire education, and diffusion of technology and democratic ideas. The net income implications for those left behind are uncertain. This article reviews the main transmission channels investigated in the existing literature and uses a standard development accounting framework to provide estimates of their relative strength and of their combined effect. Although skill biased, emigration increases the disposable income of those left behind in no fewer than three-quarters of the countries of the world. This result is robust to variations in the set of parameter values within a reasonable spectrum established in the empirical literature.
Docquier, F. & S. Veljanoska (2022). Brain Drain vs. Brain Gain. In: Zimmermann, K.F. (eds), Handbook of Labor, Human Resources and Population Economics, Springer, Cham., 1-27.
Due to self-selection and skill-selective immigration policies, highly educated individuals exhibit much greater propensity to emigrate internationally than the less educated. Although skill-biased emigration has long been viewed as detrimental to the growth potential of the sending country, recent studies emphasize the fact that it also induces economic benefits. This chapter reviews the existing literature on brain drain and development, documents global selection patterns, and provides updated estimates of the (net) effect of skill-biased emigration on human capital formation, human capital accumulation, and macroeconomic performance for almost every country in the world. The quantitative analysis suggests that skill-biased emigration can be beneficial for human development and economic growth in most countries at the bottom of the income distribution as well as in some middle-income countries.
Cha’ngom, N. & C. Deuster & F. Docquier & J. Machado (2022). Selective Migration and Economic Development: A Generalized Approach.
International migration is a selective process that induces ambiguous effects on human capital and economic development in the countries of origin, global inequality and extreme poverty. To quantify these effects, we propose a generalized approach that establishes the micro-foundations of the relationship between selective emigration and human capital accumulation in a multi-country context, and embeds this migration-education nexus into a development accounting framework. We find that selective emigration stimulates human capital accumulation and the income of those remaining behind in a majority of countries, in particular in the least developed ones. The magnitude of the effect varies according to the level of development, the dyadic structure of migration costs, and the education policy. Emigration significantly reduces cross-country disparities in income per capita, as well as the proportion of extreme poor in the world population.
Link to Manuscript
The brain gain mechanisms holds true in the medical sector.
Adovor, E. & M. Czaika & F. Docquier & Y. Moullan (2021). Medical brain drain: how many, where and why? Journal of Health Economics, 76, 102409.
We build a new database documenting the evolution of physician migration over a period of 25 years (1990–2014), and use it to empirically shed light on its determinants. In relative terms, the highest emigration rates are observed in small island nations and low-income countries, where needs-based deficits of healthcare workers are often estimated to be most severe. Over time, we identify rising trends in Caribbean islands, Central Asia and Eastern Europe. On the contrary, despite increasing migration flows to Western Europe, physician migration rates from sub-Saharan Africa have been stable or even decreasing. Our empirical analysis reveals that physician migration is a complex phenomenon that results from a myriad of push, pull, and dyadic factors. It is strongly affected by the economic characteristics of origin and destination countries. The sensitivity to these push and pull factors is governed by linguistic and geographic ties between countries. Interestingly, we find that the evolution of medical brain drain is affected by immigration policies aimed at attracting high-skilled workers. In particular, physician migration is sensitive to visa restrictions, diploma recognition, points-based system, tax breaks towards migrants, and the option of obtaining a permanent resident status.
Adovor, E. & F. Docquier & Z. Kone (2021). Physician brain drain, medical training, and shortage of healthcare personnel across the globe.
We exploit a new dataset on physicians’ emigration and medical training to investigate whether reversing or stopping physician brain drain could help reduce shortages of medical doctors and improve access to medical services in sending countries. Using dynamic panel regressions, and combining internal and external instruments, we find evidence of a positive effect of emigration prospects on medical training. The short-run effect is small, implying that a marginal increase in emigration exacerbates shortages of physicians practicing in most countries within a period of 5 years. The long-run elasticity is larger, however, implying that increasing emigration gradually spurs the long-run stock of physicians practicing at the sending country when emigration rate remains below 15%. Contrary to popular wisdom, we find that policies aiming to reverse or stop the emigration of physicians might reduce their worldwide stock and aggravate their shortage in about 80% of countries.
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A net brain gain requires good international connectivity and access to education. In poor countries, the brain gain benefits the richest regions only. Isolated regions with poor education infrastructure incur human capital losses.
Bocquier, P. & N. Cha’gnom & F. Docquier & J. Machado (2023). The Within-Country Distribution of Brain Drain and Brain Gain Effects: A Case Study on Senegal.
Existing empirical literature provides converging evidence that selective emigration boosts human capital accumulation in the world’s poorest countries. However, the within-country distribution of such brain gain effects has been largely disregarded. Focusing on Senegal, we provide evidence that the brain gain mechanism benefits the richest regions that are internationally connected and have better access to education. Human capital responses are negligible in regions lacking international connectivity, and even negative in better connected regions with poor access to education. These results also pertain to internal migration, suggesting that highly vulnerable populations are trapped in the least developed areas. Designing policies to improve connectivity and access to education is of prime importance to combat extreme poverty and realize the 2030 Agenda’s principle of leaving-no-one-behind.
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Extreme weather shocks have ambiguous effects on people mobility. It is empirically challenging to identify robust and general climate migration patterns from the past decades.
Aoga, J. & J. Bae & S. Veljanoska & S. Nijssen, P. Schaus (2020). Impact of weather factors on migration intention using machine learning algorithms.
A growing attention in the empirical literature has been paid to the incidence of climate shocks and change in migration decisions. Previous literature leads to different results and uses a multitude of traditional empirical approaches. This paper proposes a tree-based Machine Learning (ML) approach to analyze the role of the weather shocks towards an individual’s intention to migrate in the six agriculture-dependent-economy countries such as Burkina Faso, Ivory Coast, Mali, Mauritania, Niger, and Senegal. We perform several tree-based algorithms (e.g., XGB, Random Forest) using the train-validation-test workflow to build robust and noise-resistant approaches. Then we determine the important features showing in which direction they are influencing the migration intention. This ML-based estimation accounts for features such as weather shocks captured by the Standardized Precipitation-Evapotranspiration Index (SPEI) for different timescales and various socioeconomic features/covariates. We find that (i) weather features improve the prediction performance although socioeconomic characteristics have more influence on migration intentions, (ii) country-specific model is necessary, and (iii) international move is influenced more by the longer timescales of SPEIs while general move (which includes internal move) by that of shorter timescales.
Bertoli, S. & F. Docquier & H. Rapoport & I. Ruyssen (2022). Weather Shocks and Migration Intentions in Western Africa: Insights from a Multilevel Analysis. Journal of Economic Geography, 22(2), 289-323.
We use a multilevel approach to investigate whether a general and robust relationship between weather shocks and (internal and international) migration intentions can be uncovered in Western African countries. We combine individual survey data with measures of localized weather shocks for 13 countries over the 2008–2016 period. A meta-analysis on results from about 51,000 regressions is conducted to identify the specification of weather anomalies that maximizes the goodness of fit of our empirical model. We then use this best specification to document heterogeneous mobility responses to weather shocks. We find that variability in Standardized Precipitation Evapotranspiration Index/rainfall is associated with changing intentions to move locally or internationally in a few countries only. However, the significance, sign and magnitude of the effect are far from being robust and consistent across countries. These differences might be due to imperfections in the data or to differences in long-term climate conditions and adaptation capabilities. They may also suggest that credit constraints are internalized differently in different settings, or that moving internally is not a relevant option as weather conditions are spatially correlated while moving abroad is an option of last resort. Although our multilevel approach allows us to connect migration intentions with the timing and spatial dimension of weather shocks, identifying a common specification that governs weather-driven mobility decisions is a very difficult, if not impossible, task, even for countries belonging to the same region. Our findings also call for extreme caution before generalizing results from specific case studies.
Bocquier, P. & M. Cissé & Y. Schenk (2023). The climate migration nexus revisited: New evidence from Senegal.
We examine the impact of climate anomalies on migration patterns in Senegal, where millions of individuals rely on rain-fed agriculture for their livelihoods. Utilizing comprehensive data from the 2013 Senegalese census, which includes 13 million individuals, and incorporating novel data on fine-grained drought measures, we assess mobility responses to climate variability. We show that the aggregate agricultural output is particularly dependent on rainfall in Senegal. Estimating a gravity model of medium-run internal migration flows over two 5-year migration episodes between 426 localities, we show that the exposure to droughts was caused lower migration rates at rural origin localities. On the other side, exceptionally wet growing seasons were linked to higher migration rates. The results suggest the presence of severe financial constraints limiting the potential of costly migratory moves for those depending on income from agricultural activities. Our findings challenge the prevailing climate-migration narrative and calls for special consideration of the needs for those left behind.
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David, A. & F. Docquier (2021). Special issue on Climate Migration. Journal of Economic Demography, 87(3).
How do weather shocks influence human mobility and poverty, and how will long-term climate change affect future migration over the course of the 21st century? These questions have gained unprecedented attention in public debates as global warming is already having severe impacts around the world, and prospects for the coming decades get worse. Low-latitude countries in general, and their agricultural areas in particular, have contributed the least to climate change but are the most adversely affected. The effect on people’s voluntary and forced displacements is of major concern for both developed and developing countries. On 18 October 2019, Agence Française de Développement (AFD) and Luxembourg Institute of Socio-Economic Research (LISER) organized a workshop on Climate Migration with the aim of uncovering the mechanisms through which fast-onset variables (such as weather anomalies, storms, hurricanes, torrential rains, floods, landslides, etc.) and slow-onset variables (such as temperature trends, desertification, rising sea level, coastal erosion, etc.) influence both people’s incentives to move and mobility constraints. This special issue gathers five papers prepared for this workshop, which shed light on (or predict) the effect of extreme weather shocks and long-term climate change on human mobility, and stress the implications for the development community.
Kondi, K. & S. Veljanoska (2023). Internal Migration as a Response to Soil Degradation: Evidence from Malawi. LIDAM Discussion Papers, 202304.
We study how the slow deterioration of soil, caused by climate change, affects internal migration and household resettlement. Rural households are expected to move when they face worsening soil conditions, as soil degradation is detrimental to agricultural productivity. The other possibility is that they can get stuck in a poverty trap. We use the Integrated Household Survey in Malawi for the years 2010-2016. Soil depletion is not a random process and to account for its endogeneity, we instrument soil degradation by using distant climate shocks and controlling for recent weather conditions. We find that severe soil nutrient constraints push households to send their members away. The underlying mechanism is that soil degradation is harmful to agricultural productivity, and therefore food security, which incentivizes households to seek better opportunities by pushing their members to migrate.
Integration for the 21th century¶
Socio-demographic changes in general, and population and education disparities in particular, will continue to shape future migration pressures.
Dao, T.H. & F. Docquier & M. Maurel & P. Schaus (2018). Global migration in the 20th and 21st centuries: the unstoppable force of demography. Review of World Economics, 157, 417-449.
This paper sheds light on the global migration patterns of the past 40 years, and produces migration projections for the 21st century. To do this, we build a simple model of the world economy, and we parameterize it to match the economic and socio-demographic characteristics of the world in the year 2010. We conduct backcasting and nowcasting exercises, which demonstrate that our model fits very well the past and ongoing trends in international migration, and that historical trends were mostly governed by demographic changes. Then, we describe a set of migration projections for the 21st century. In line with the backcasts, our world migration prospects are mainly governed by socio-demographic changes. Using immigration restrictions or development policies to curb these pressures requires sealing borders or triggering unprecedented economic takeoffs in migrants’ countries of origin. Increasing migration is thus a likely phenomenon for the 21st century.
Docquier, F. (2018). Long-term trends in international migration: lessons from a macroeconomic model. Economics and Business Review 4(18-1), 3-15.
In this paper I develop a stylized model of the world economy and use it to explain the long-run trends in international migration. The model very well fits the trends of the last 40 years which are mainly governed by the evolution of population disparities between industrialized and developing countries. Then I provide migration projections for the 21st century and show that future migration is also governed by socio-demographic changes. I predict a robust increase in immigration pressures from sub-Saharan Africa and MENA countries to European countries.
Impoverishing poor people does not lead to more international migration from poor countries. Migration responses to climate change will be internal.
Burzynski, M. & C. Deuster & F. Docquier & J. de Melo (2022). Climate change, Inequality and Human Migration. Journal of the European Economic Association, 20(3), 1145-1197.
This paper investigates the long-term implications of climate change on global migration and inequality. Accounting for the effects of changing temperatures, sea levels, and the frequency and intensity of natural disasters, we model the impact of climate change on productivity and utility in a dynamic general equilibrium framework. By endogenizing people’s migration decisions across millions of 5×5 km spatial cells, our approach sheds light on the magnitude and dyadic, education-specific structure of human migration induced by global warming. We find that climate change strongly intensifies global inequality and poverty, reinforces urbanization, and boosts migration from low- to high-latitude areas. Median projections suggest that climate change will induce a voluntary and a forced permanent relocation of 62 million working-age individuals over the course of the 21st century. Overall, under current international migration laws and policies, only a small fraction of people suffering from the negative effects of climate change manages to move beyond their homelands. We conclude that it is unlikely that climate shocks will induce massive international flows of migrants, except under combined extremely pessimistic climate scenarios and highly permissive migration policies. In contrast, poverty resulting from climate change is a real threat to all of us.
Burzynski, M. & C. Deuster & F. Docquier & J. de Melo (2019). Climate migration frightens… climate poverty is frightening. VoxEU.
There has been much discourse on how long-term climate change will affect human mobility over the course of the 21st century. This column estimates the long-term welfare and mobility responses to climate change. Depending on the scenario, climate change will force between 210 and 320 million people to move, mostly within their own countries. Massive international flows of climate refugees are unlikely, except under generalized and persistent conflicts. The poorest economies will be hardest hit, thus increasing global inequality and extreme poverty.
Burzynski, M. & F. Docquier & H. Scheewel (2021). Geography of climate migration. Journal of Demographic Economics, 87(3), 345-381.
In this paper, we investigate the long-term effects of climate change on the mobility of working-age people. We use a world economy model that covers almost all the countries around the world, and distinguishes between rural and urban regions as well as between flooded and unflooded areas. The model is calibrated to match international and internal mobility data by education level for the last 30 years, and is then simulated under climate change variants. We endogenize the size, dyadic, and skill structure of climate migration. When considering moderate climate scenarios, we predict mobility responses in the range of 70–108 million workers over the course of the twenty-first century. Most of these movements are local or inter-regional. South–South international migration responses are smaller, while the South–North migration response is of the “brain drain” type and induces a permanent increase in the number of foreigners in OECD countries in the range of 6–9% only. Changes in the sea level mainly translate into forced local movements. By contrast, inter-regional and international movements are sensitive to temperature-related changes in productivity. Lastly, we show that relaxing international migration restrictions may exacerbate the poverty effect of climate change at origin if policymakers are unable to select/screen individuals in extreme poverty.
Effectiveness of legal framework¶
Future education policies and international mobility frictions will impact income convergence vs. divergence. Without drastic changes, international migration policies and laws will have limited effects on global inequality.
Burzynski, M. & Ch. Deuster & F. Docquier (2020). Geography of skills and global inequality. Journal of Development Economics, 142, Article 102333.
This paper analyzes the factors underlying the evolution of the worldwide distribution of skills and their implications for global inequality. We develop and parameterize a two-sector, two-class, world economy model that endogenizes education and mobility decisions, population growth, and income disparities across and within countries. First, our static experiments reveal that the geography of skills matters for global inequality. Low access to education and sectoral misallocation of skills substantially influence income in poor countries. Second, we produce unified projections of population and income for the 21st century. Assuming the continuation of recent education and migration policies, we predict stable disparities in the world distribution of skills, slow-growing urbanization in developing countries, and a rebound in income inequality. These prospects are sensitive to future education costs and to internal mobility frictions, which suggests that policies targeting access to all levels of education and sustainable urban development have a long-term impact on demographic growth and global inequality.
Relaxing international migration restrictions slightly may exacerbate the poverty responses to climate change if decision-makers are unable to screen individuals in extreme poverty. Strengthening restrictions has limited effect on poverty.
Burzynski, M. & C. Deuster & F. Docquier & J. de Melo (2022). Climate change, Inequality and Human Migration. Journal of the European Economic Association, 20(3), 1145-1197.
This paper investigates the long-term implications of climate change on global migration and inequality. Accounting for the effects of changing temperatures, sea levels, and the frequency and intensity of natural disasters, we model the impact of climate change on productivity and utility in a dynamic general equilibrium framework. By endogenizing people’s migration decisions across millions of 5×5 km spatial cells, our approach sheds light on the magnitude and dyadic, education-specific structure of human migration induced by global warming. We find that climate change strongly intensifies global inequality and poverty, reinforces urbanization, and boosts migration from low- to high-latitude areas. Median projections suggest that climate change will induce a voluntary and a forced permanent relocation of 62 million working-age individuals over the course of the 21st century. Overall, under current international migration laws and policies, only a small fraction of people suffering from the negative effects of climate change manages to move beyond their homelands. We conclude that it is unlikely that climate shocks will induce massive international flows of migrants, except under combined extremely pessimistic climate scenarios and highly permissive migration policies. In contrast, poverty resulting from climate change is a real threat to all of us.