World Migration Report 2024: Chapter 2
International migration flows
While data on migrant stocks are widely available, data on global migration movements (flows) are much more limited. Available UN DESA estimates on global migrant stocks are extensive and global in scope; however, the database of migration flows only encompasses 45 countries.10 Capturing data on migration flows is extremely challenging for several reasons. First, while international migration flows are generally accepted as covering inflows and outflows into and from countries, there has been a greater focus on recording inflows. For example, while countries such as Australia and the United States record cross-border movements, many others only count entries and not departures.11 Additionally, migration flow data in some countries are derived from administrative events related to immigration status (for example, issuance/renewal/withdrawal of a residence permit), which are then used as proxies for migration flows. Furthermore, migratory movements are often hard to separate from non-migratory travel, such as tourism or business.12 Tracking migratory movements also requires considerable resources, infrastructure and ICT/knowledge systems. This poses particular challenges for developing countries, where the ability to collect, administer, analyse and report data on mobility, migration and other areas is often limited. Finally, many countries’ physical geographies pose tremendous challenges for collecting data on migration flows. Entry and border management, for example, is particularly challenging in some regions because of archipelagic and isolated borders, and is further complicated by traditions of informal migration for work.13
Conflating “migration” and “migrant”
In a general sense, migration is the process of moving from one place to another. To migrate is to move, whether from a rural area to a city, from one district or province in a given country to another in that same country, or from one country to a new country. It involves action.
In contrast, a migrant is a person described as such for one or more reasons, depending on the context (see the text box on “Defining migration, migrant and other key terms” above). While in many cases “migrants” do undertake some form of migration, this is not always the case.
In some situations, people who have never undertaken migration may be referred to as migrants – children of people born overseas, for example, are commonly called second- or third-generation migrants.a This may even extend to situations involving statelessness, whereby whole groups of people are not able to access citizenship, despite being born and raised in a country. Such people may even be referred to as irregular migrants by authorities.b
There are currently two main data sets on international migration flows, both of which are derived from national statistics: UN DESA’s International Migration Flows data set and OECD’s International Migration Database. Since 2005, UN DESA has compiled data on the flows of international migrants to and from selected countries, based on nationally available statistics. At the time of writing (October 2023), there had been no update to the UN DESA flows data set, with the most current being the 2015 version. The 2015 migration flows data set comprises data from 45 countries, up from 29 countries in 2008 and 15 countries in 2005.14
The OECD has been collecting international migration flow data since 2000, allowing for trend analysis to be conducted over a subset of major destination countries, depicted in Figure 6 (although data are not standardized, as explained in the note under the figure). The latest available data indicate that in 2020, there was a sharp decline in permanent migration inflows from the year before, a reflection of the border closures and movement restrictions in response to the COVID-19 pandemic. There were more than 8 million inflows in 2019. This dropped to around 5 million in 2020, but has since risen to reach 5.9 million in 2021, comprising both labour and humanitarian migrants; some recent estimates from the OECD indicate that 2022 saw a further increase in inflows over 2021, connected mainly to humanitarian displacement15
Source: OECD, n.d.a.
Note: Data are not standardized and therefore differ from statistics on permanent migration inflows into selected countries contained in OECD’s International Migration Outlook series. The 35 countries typically included in OECD statistics are the following: Australia, Austria, Belgium, Canada, Chile, Czechia, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Israel, Italy, Japan, Latvia, Luxembourg, Mexico, the Kingdom of the Netherlands, New Zealand, Norway, Poland, Portugal, the Republic of Korea, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye, the United Kingdom and the United States of America. In some years, data for particular countries are not available: data were made available for 31 countries in 2000. Notably, data for Greece have not been reported between 2000 and 2004, and data for Türkiye were reported only for 2010, 2016, 2017 and 2018. Please refer to the OECD’s International Migration Outlook series for explanatory notes.
Collaboration with the private sector on new data to understand migration flows better
Over the past several years, the private sector has begun offering novel data sources useful in several areas of migration-related statistics. For example, the Data for Good at Meta programme, which builds privacy preserving datasets to advance social issues, began modelling displacement from weather-based events through a partnership with the Internal Displacement Monitoring Centre (IDMC) starting in 2018. These tools were used by IDMC and others to triangulate official sources on displacement in the aftermath of major events such as Typhoon Hagibis, the strongest typhoon to strike mainland Japan in decades.
More recently, researchers at Harvard, the European Commission’s Joint Research Centre, and Meta published an IOM Migration Research Series paper on new aggregated social media data to anticipate conflict-induced migration flows in the context of the war in Ukraine. They found that the publicly available Facebook Social Connectedness Index is a strong predictor of diaspora populations within 27 European Union Member States, which is itself predictive of displacement trajectories of those uprooted by conflict.
Additional research is currently underway from Meta and their collaborators on predicting international migration flows building upon items showcased at the 3rd International Forum on Migration Statistics. IOM and other collaborators have helped guide the development of a global dataset estimating international migration flows, forthcoming in 2024, with analysis of country-to-country trends spanning the COVID-19 pandemic years. This new international dataset is poised to provide a critical input into understanding international migration flows, most profoundly in developing countries where existing flow data is often unavailable. Partnerships like those with Meta have the potential to significantly improve the way migration statistics are calculated in the years to come.
Unsafe migration flows
Some migration routes pose many more challenges than others, for migrants as well as for authorities. Migrants’ journeys can sometimes be characterized by unsafe and even deadly outcomes, often related to a range of social, political, economic, environmental and policy factors that can profoundly impact the way in which people undertake migration.16 In the wake of the tragic events of October 2013, in which more than 360 people died in the sinking of two boats near the Italian island of Lampedusa, IOM began collecting and compiling information on migrants who perish or go missing on migratory routes worldwide, as part of its Missing Migrants Project.17 Data sources include official records of coastguards and medical examiners, media stories, reports from non-governmental organizations and United Nations agencies, and interviews with migrants.18
The number of deaths recorded in 2023 (over 8,500) was the highest since 2016 and a significant increase over the previous three years, especially 2020, when the COVID-19 pandemic and related mobility restrictions resulted in a lower overall number of deaths (Figure 7). Between 2014 and end of 2023, IOM’s Missing Migrants Project recorded over 63,000 deaths and disappearances on migration routes. Year-to-year, 2023 saw an increase in deaths across the Mediterranean, Africa and Asia, with an unprecedented number of lives lost across the latter two regions.19
Note: Data include recorded deaths as well as those reported as missing. See the Missing Migrants Project webpage for details of methodology and geographic regions.
The Missing Migrants Project faces notable challenges in its data collection. For instance, most recorded deaths are of people travelling via clandestine routes, which are often at sea or in remote areas to evade detection, meaning remains are often not found. Few official sources collect and make data on migrant deaths publicly available. Relying on testimonies of fellow migrants and media sources can be problematic due to inaccuracies and incomplete coverage. Nevertheless, the project sheds light on a previously under-researched and neglected topic, highlighting the need to address this tragic ongoing issue, including in the context of the implementation of the Global Compact for Safe, Orderly and Regular Migration.