Causes and drivers of international migration

Classical macro-economic theory posits that income differential between origin and destination communities and countries are a primary determinant of migration. Newer economic theories add that households use migration to reduce economic risk by diversifying their sources of income. For example:

• Some members of the household remain at home, engaging in subsistence agriculture, while others move to urban areas to engage in wage employment.
• Still others may migrate internationally to gain even higher wages and ensure that the household is protected against local or national economic crises.
• Remittances from those earning more to those with fewer options help equalize income within the household.

Further economic theory posits that the very nature of the global economy makes it likely that people will migrate from poorer, less skilled countries to wealthier, more highly skilled ones. As education level rises in wealthy countries, there are fewer native-born willing to work at the wages and under the working conditions offered for lesser skilled jobs, offering opportunities for migrants to fill economic niches.

Economic differences between nation states are widening, increasing the motivation for economically motivated migration. The world's GDP (considering parity in purchasing power --PPP) was US$47.2 trillion in 1990 and expanded to more than US$ 116.7 trillion in 2017 (World Bank, 2019a). Overall, per capita income (in constant US$) tripled from about US$5446.1 in 1990 to an estimated US$16940.8 in 2017 (World Bank, 2019b). Variation among countries is extremely large, however. Per capita income in Qatar, for example, was estimated to be among the highest at US$128,378.3 in 2017 whereas it was among the lowest, at only US$725.9, in the Central African Republic (World Bank, 2019c). It should be noted, however, that the poorest of the poor seldom have the resources needed to migrate internationally; poor people from the least developed countries are more likely to move internally or to neighboring countries that provide better economic opportunities, if at all.

Most migrants are young people seeking work. According to the ILO, youth unemployment has decreased from the extremely high rates immediately after the recession of 2008 but still exceed the pre-recession levels. It is particularly high in the Arab States (29.7% in 2018), Northern Africa (28.6%), Latin America and the Caribbean (19.5%), and Central and Western Asia (17.4%) (International Labor Organization, 2019). Young people are also more likely to be underemployed or in jobs that are highly vulnerable to frequent periods of unemployment.

International migration will also be affected by the future of work, as evident in three examples. First, as countries develop, they often require fewer agricultural workers to produce the food they consume. Disengaged agricultural workers often move from rural to urban areas in response to this trend. Second is the growth of global corporations with their own multinational workforces. These companies move staff among the countries in which they operate but may also have factories operating in multiple countries around the world, providing new employment opportunities in lower-income companies. Third is the importance of information technology, especially artificial intelligence (AI), as a driver of productivity. Whether AI and robotics will displace workers, driving down need for migration, or introduce new economic niches with rising demand for workers is at present unknown.

New trends: The future of work

Future of work and agriculture: migration as an adaptation strategy

In 2018, about 26.5 percent of the world’s workers were employed in agriculture, down from 43.2 percent in 1991 (International Labor Organization, 2019). In low income countries, however, 65.2 percent of male and 69.8 percent of female workers are still in agriculture (World Bank, 2019). By contrast, only 3.2 percent of male and 2.0 percent of female workers in high income countries are employed in that sector (World Bank, 2019). In low-income countries, those employed in agriculture are usually small farmers or hired workers, many using rain-fed farming techniques, as opposed to mechanized irrigation. Farmers in these countries generally have lower-than-average incomes and often grow little more than can feed their own families. Both internal migration to urban areas and international movements are proven methods of managing risks associated with agricultural work, particularly in conditions of persistent or recurrent droughts.

Such migration has implications more generally. First, ex-farmers everywhere are most likely to accept so-called 3-D (dirty, dangerous, difficult) jobs. Second, rural to urban migration within a country can serve as a stepping-stone to international migration. Ex-farmers who must find new jobs often make physical as well as cultural transitions when they move to cities. Some may find adaptation in a foreign city as easy as integration in larger cities within their countries. This is particularly the case if past migration from their areas of origin has resulted in settled friends and relatives abroad. International migration is also less expensive for those already living in urban areas of their own countries because they are physically closer to transportation hubs and to government agencies that provide passports and visas.

Future of work and multinational corporations: implications for lower-skilled migrant workers

A further economic trend influencing current and future migration is the globalization of the labour market as multinational corporations see their workforces in global, not purely national terms. Similarly, corporations use contingent labour and contract out assignments at an unprecedented rate.  In manufacturing, it is common for components of a single product to be made in several different countries through subsidiaries of the same company or contractors. The corporate interest in moving its labour force to meet the demands of this type of scheduling across subsidiaries and contractors often runs into conflict with immigration policies.

Governments are often willing to accommodate the interest of these corporations in moving their executives, managers, professionals and staff with specialized knowledge of their business practices into positions throughout the world regardless of their nationality. More controversial is the international mobility of lesser skilled personnel, often to work on contracts that these companies receive. Whether these movements involve companies building infrastructure in lesser developed countries, companies vying for contracts in other higher income countries, or subcontractors applying for work visas for computer programmers and other specialists, they raise questions about the meaning of fair trade and potential competition of foreign workers with domestic labour.

Future of work and Artificial Intelligence: challenges and opportunities for migrant workers

Information technology, in general, and artificial intelligence, more specifically, will also change the future of work and have implications for migration. As described by the consulting firm McKinsey, “The development of automation enabled by technologies including robotics and artificial intelligence brings the promise of higher productivity, increased efficiencies, safety, and convenience, but these technologies also raise difficult questions about the broader impact of automation on jobs, skills, wages, and the nature of work itself. (McKinsey Global Institute, 2017).” Telework arrangements already allow employees to work from where they live, rather than where the company has its headquarters. As communications improve, such options will likely multiply. Social media already provides invaluable information to those wanting to migrate.

In some cases, new technology reduces the need for migration. Companies on 24-hour production schedules may have factories operating in multiple countries around the world, providing new employment opportunities in lower-income companies. Artificial intelligence and robotics may well displace workers in both lesser and more highly skilled jobs. McKinsey found that about “60 percent of all jobs have at least 30 percent of activities that are technically automatable, based on technologies available today (McKinsey Global Institute, 2017).” Availability of inexpensive labor, including through international migration, will influence the adoption of new technologies at the same time that technology will affect the need for workers from other countries. At the same time, however, technology is likely to create new businesses, job opportunities and professions that are unknown today. This occurred during the industrial revolution when manufacturing advances and new labor-saving inventions eliminated many jobs while creating many others—in some cases, more than could be filled by the native workforce.

Fertility rates and replacement migration

While population growth has slowed in many parts of the world, the momentum from past and present fertility rates means that the world’s population will continue to grow even as future fertility falls. World population in 2018 totalled 7.6 billion, an increase from less than 1.5 billion one hundred years earlier (US Census Bureau, 2018). More than 83 percent of the world’s population is in the developing world (Population Reference Bureau, 2018). World fertility rates (that is, number of children per woman) have dropped to 2.4 children per woman, but fertility in the least developed countries remains high at 4.5 children per woman (Population Reference Bureau, 2018). Fertility in more developed countries is much lower at 2.1 (Population Reference Bureau, 2018). Without immigration, these very different fertility patterns mean that the population shares of the world’s countries will change during the next decades.

Rising demographic and economic differences combine with a third major difference among countries: political drivers. Among political dynamics that have spurred migration three stand out:

Displacement due to conflict

After the global conflict between capitalism and communism ended in the early 1990s, local conflicts erupted in many areas, leading to physical and political instability, separatist movements, new nations, and more migrants. In addition, failed States, ethnic cleansing and genocide produced millions of refugees and displaced persons who were unable to remain safely in their home communities. Violence, kidnappings, rapes and other manifestations of insecure societies induced still more people to migrate in search of safety. Some of the displaced population may be defined as refugees (as discussed below) while others are internally or internationally displaced without the legal protections afforded to refugees. In these cases, the governments of the countries of origin may be implicated in the actions that displace people. In others, non-State actors ranging from insurgent forces and terrorist organizations to family members may threaten the security of those who are displaced. These forms of violence are often gendered, with boys and young men often pressured or forced into military service and girls and young women subject to forced military recruitment, albeit in smaller numbers, sexual violence and human trafficking. The key to whether people are forced to flee lies in the extent to which governments have the capacity and will to intercede on behalf of potential victims and provide their own protection.

As with the other drivers of migration, environmental factors are seldom determinative on their own (See chapter Migration, Environment and Climate Change for more information). Rather, they operate through other drivers, particularly the impact on livelihoods and shelter as well as the capacity and willingness of governments to protect people from the negative impacts of environmental disasters (see, for example, (Black, et al., 2011) (Ginetti, 2015), (Hugo, 2011), (Kniveton, Smith, & Wood, 2011). Yet, environmental changes, particularly in the context of climate change, can have profound consequences. According to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), “climate change over the 21st century is projected to increase displacement of people (Intergovernmental Panel on Climate Change, 2014, p. 20).”

There appears to be four principal pathways by which environmental drivers in general, and climate change specifically, affects migration patterns:

• Recurrent and persistent droughts that undermine livelihoods, especially in rural communities that rely on rain-fed agriculture. These combine with desertification, land degradation and habitat/ecosystem loss that also affect livelihoods.
• Rising sea levels and coastal erosion that over time make vast areas of land uninhabitable or undermine livelihoods such as agriculture.
• Acute disasters linked to natural hazards (only some of which are climate-related) that appear more frequently and more intensely, such as earthquakes, floods, fires, tornadoes, tsunamis, and cyclones.
• Conflicts over scarce resources, most of which are within countries and can lead to political instability; communal, ethnic and religious divisions; and mass displacement of people.

The more detailed evidence reviewed by the IPCC suggest that “[e]extreme weather events provide the most direct pathway from climate change to migration” but in the longer term, “sea level rise, coastal erosion, and loss of agricultural productivity (…) will have a significant impact on migration flows” (Adger, et al., 2014, pp. 767, 768-9).

Pre-existing levels of resilience give some households greater capacity to cope with environmental drivers while making others more vulnerable. These can have different impacts. On the one hand, the more resilient may have greater ability to stay in situation and adapt to environmental change; on the other hand, resilience also gives people the financial, social and human resources needed to migrate. The most vulnerable will be the most adversely affected but they will also be the least able to migrate any distance from their homes.

Customs and social transformation of communities and societies are key drivers of migration. For instance:

• Cultural and societal roles may consign people to remain at home (despite their own wish to move) or give them the opportunity to go elsewhere.
• Discriminatory and persecutory policies and practices based on social and cultural precepts may trap people in place, or, in turn, may force them to flee from harm’s way. For example, social and cultural attitudes about sexual orientation, female labour force participation, female genital mutilation, and domestic violence can take away the means through which people can migrate or be important drivers of migration not only for those directly affected but others who do not share these values.
• As societies change, opportunities may arise for migration by choice not necessity. This can sometimes result from the social remittances that migrants send home in terms of new values and principles. For example, as women have gained greater autonomy, the potential to migrate for their own employment or education has grown significantly.

Also, social networks are one of the most important drivers of migration because they enable migrants to access information and resources needed to cross national borders, obtain employment and housing on arrival, and integrate into new communities. Explaining the importance of these social networks, a team of academic experts stated: “They increase the likelihood of international movement because they lower the costs and risks of movement and increase the expected net returns to migration” (Massey, et al., 1993). As more people within the networks migrate, they can help others move. Given the strength of these networks, it is not surprising that migrants from the same geographic areas of source countries tend to settle in the same neighbourhoods in destinations. Already settled migrants use social capital they have amassed in the new community to help new arrivals find accommodations and jobs, enroll their children in schools, obtain needed documentation, and so forth. The social networks importantly reduce the psychological barriers to long-distance migration as they provide emotional support in the new location. Social networks also often help families left behind in source countries until the migrants can send remittances.

Relatively few of those affected by the macro drivers described above actually migrate, especially to other countries. Carling (2002) posits that there are four distinct groups measured by their propensity to migration:

• Those who voluntarily move;
• Those who involuntarily move;
• Those who voluntarily remain at home;
• Those who involuntarily remain in situ even though they might prefer to migrate.

To understand migration then requires analysis of the facilitators and barriers not only to movement but also to immobility.

Some of these facilitators and barriers to movement and immobility relate to household, family and individual characteristics of the affected populations. Socio-economic characteristics of families and individuals within those households are one of the most important of the micro drivers of international migration. The very poorest of the poor tend not to be as mobile as others, largely because they lack the forms of capital needed to successfully relocate. They generally have few financial resources to undertake what is often an expensive enterprise; their human resources—generally measured in education and skills—are also inadequate or non-transferrable to a new location; and their social capital may be lacking if they do not have networks already abroad. Not all forms of capital induce migration, though. For example, land- or business-owning households may have little financial need for all or some members to migrate or be reluctant to leave their property behind.

Even in situations of forced migration, socio-economic characteristics may play a role in determining first, whether people will leave their home communities and second, where they go to find greater safety. Families measure the risks and benefits of staying in place against those of flight for each member. The risks vary depending on many personal factors—including gender, age, sexual orientation, health status, size and composition of the household—as well as the nature of the threat. The involuntarily immobile may be the most at risk but the least able to flee because of pre-existing vulnerabilities. They are trapped in place despite a desperate need to migrate. As this discussion indicates, the complex nature of migration decision-making belies the simple characterization of migration as either forced or voluntary as there can be elements of both.

Other facilitators and barriers to migration and immobility influencing trends and patterns of movement are more systemic. For example, the communication revolution helps potential migrants to learn about opportunities abroad, and often provides both the motivation and the funds that encourage and enable people to move over national borders. The most trusted information about opportunities abroad comes from migrants already in the destination, since they can inform family and friends at home in a context both understand. Social media innovations allow people to learn about both opportunities and challenges in real time. They may see movies and TV shows produced in high-income countries that make recruiters’ stories about the riches attainable abroad seem plausible. Transportation innovations have also influenced migration patterns. Studies suggest the times necessary for migrants to repay the costs of transportation are much shorter than in previous historic periods, so that even migrants who pay high smuggling fees can usually repay them within two or three years (Kyle & Koslowski, 2011).

Recent discussions on the interconnections between migration and Information and communication technologies have focused on the various ways' technology impacts aspects of migration. In addition to the use of apps to share information in real-time about best routes for both regular and irregular migration, technology impacts on other aspects of migration are drawing increasing attention and scrutiny. As noted by McAuliffe (2018), these include, 

• To support the integration of migrants and refugees, various apps and technology initiatives, including developed by migrants themselves, focus on facilitating adaptation to new communities, workplaces, cultures.
• Artificial intelligence’s impact the new modes of work and implications for migrant workers
• Social media use by both human rights activists and anti-immigration groups