Theories of Migration: Why do people migrate?

Migration, whether international or domestic, voluntary or forced, is a complex process that hinges upon both individual and social factors. Traditionally, it has been viewed as a consequence of geographical differences between certain regions in terms of labor and income. However, other factors might be at play, too — such as differences in terms of quality of life and political freedom between regions. By the end of the nineteenth century, social scientists began to discuss why people migrate, and they came up with several explanations. These are the main theories that try to make sense of the causes of migration:

• Push-pull theory: It claims regions have certain factors that make people either immigrate to it or emigrate from it.
• Neoclassical theory: It claims people migrate to regions where the labor market is in need of workers, or to regions where the market better rewards their own abilities.
• Globalization theories: They claim migration may or may not be encouraged by the process of globalization.
• Dual labor market theory: It claims two kinds of people migrate to developed economies — both high-income and low-income workers.
• New Economics of Labor Migration (NELM) theory: It claims the decision to migrate is one made by entire families rather than individual people.
• Diaspora theory: It claims members of ethnic or national groups spread around the world, yet maintain close contact with one another abroad.
• Migration network theory: It claims migrants develop support networks that encourage other people to migrate too.
• Migration systems theory: It claims migration is a process that has bi-directional flows, affecting both origins and destinations of migrants.
• Migration transition theory: It claims migration varies according to the level of development of a region.

Push-Pull Theory

The push-pull theory of migration is the traditional way of understanding migration. According to it, there are many factors that make people either want to live somewhere, or want to live elsewhere. Some of them are:

• Political factors: People free regions that are experiencing violent conflicts, civil wars, increasing levels of crime, or political instability.
• Economic factors: People move in search of better jobs.
• Cultural factors: People move to regions where they feel welcome, such as regions where their native language is spoken.
• Environmental factors: People flee natural disasters, such as earthquakes, or even gradual environmental processes, such as sea level rise, which has been posing an existential threat to small island countries.
• Demographic factors: People move from densely-inhabited regions to places where there is less pressure on public services, city traffic, etc.

In the nineteenth century, Anglo-German geographer Ernst Ravenstein claimed that the primary cause for migration are economic factors. Over the following years, several scholars have challenged his argument. For instance, some authors believed that migration depends upon the distance between certain regions, the size of their respective populations, and the strength of their respective economies. Also, in 1966, Everett Lee claimed that migration depends not only on push-pull factors, but is also contingent upon the obstacles to migrate and upon the individual will to migrate.

The problem with push-pull models is that they are purely descriptive. They take many factors into consideration for explaining migration, but do a poor job of explaining the relations between them. In addition, push-pull models are unable to explain why certain regions both attract and repel migrants, and why certain migrants decide to return to their places of origin.

Neoclassical Theory

Like its counterpart in Economics, the Neoclassical theory of migration is based on the idea of equilibrium — that is, the notion that, in the long run, immigration and emigration balance one another. In general, adherents of this theory believe that migration is explained by geographical differences in labor markets. People migrate from regions that have a surplus of labor, where they are paid less, to regions that have a shortfall of labor, where they are paid more. This process makes wages increase in the source region and reduce in the destination region. Eventually, an equilibrium point is reached, and wages end up being exactly the same in both regions.

In 1970, John Harris and Michael Todaro drew inspiration from the neoclassical school of thought in order to create the Harris-Todaro model. It is a model that tries to make sense of rural-urban migration. In particular, they were concerned with the fact that rural populations continued to migrate to cities, despite urban jobs being increasingly harder to find. According to their model, the increase in urban unemployment is largely irrelevant to the decision of peasants to migrate. Rather, the model claims that urban wages are so much higher than rural ones that peasants have an incentive to migrate. Accordingly, as long as this wage difference outweighed the risk of unemployment, rural exodus would continue.

Another strand of neoclassical thought is the human capital theory, put forward by authors such as Larry Sjaastad, in 1962. He argued that people have different skills and knowledge, and that the value of their “human capital” will vary between regions. For example, in developing countries, specialized engineers might have difficulty in finding jobs that match their qualifications. In fact, this has become such a common scenario that many engineers have entered the “gig economy”, for instance by working as drivers for Uber. Accordingly, this theory claims that people will be incentivized to migrate when they believe their abilities will be better rewarded in other labor markets. A case in point is that of younger people, who generally are better educated and, as such, expect bigger salaries than those that are currently available where they live.

Neoclassical theories of migration are usually criticized for their assumptions. They assume people are rational and have perfect information regarding the wage differences between regions. Also, they assume migration is unimpeded. However, accurate information about wages in other regions might not be easy to come by, and, even then, people might decide not to migrate based on emotional preferences, despite rational benefits. Additionally, in the real world, there are several obstacles to migration, particularly in developed countries whose labor markets pay better — visas, border checks, border walls and even xenophobia, all of which might discourage or inhibit migration.

Globalization Theories

Globalization is the process by which the world becomes more integrated, with people, companies and governments engaging in ever-increasing flows and interactions. This process can be seen either positively or negatively. In a globalized world, migration is always both encouraged and discouraged:

• Thanks to the improvements in communication and transportation technologies, it has never been easier to migrate — notwithstanding political barriers to migration. At a distance, people can see how life is elsewhere and might be tempted to move by taking advantage of mature transportation networks, such as sea and air routes.
• At the same time, also because of communication and transportation technologies, migration might be unnecessary, because people can easily go to another region, then head back to their original place of residence. Nowadays, for instance, there are tons of people who engage in pendular migration: the regular movement between one’s residence and one’s workplace, typically in different cities. Also, there are those who benefit from working holiday visas: those that allow migrants to work in a foreign country for an extended, albeit temporary, period.

According to Marxist scholars of world politics, such as Immanuel Wallerstein, globalization makes migration no longer purely contingent upon the wishes of individual people. Instead, they believe migration is a consequence of systemic interactions that reinforce global inequalities, because highly-educated workers usually leave their home countries and move to developed countries. An evidence of this is the fact that states generally attempt to facilitate the migration of only those people that have abundant money or knowledge, by providing them with “golden visas” or “extraordinary abilities visas”. In the words of Polish sociologist Zygmunt Batman, “The riches are global, the misery is local”.

One criticism of Marxist theories about the relation between globalization and migration is that skilled workers may truly improve their lives by migrating — that is, they are not necessarily helpless victims of global capitalism.

Dual Labor Market Theory

The dual labor market theory was put forward by authors such as Michael Piore, in the book Birds of Passage: Migrant Labor and Industrial Societies, which was published in 1979. This theory stresses that developed economies need two kinds of labor, thus they attract two entirely different kinds of migrants:

• Highly-skilled workers: They are handpicked for their “human capital”, or for belonging to a certain privileged elite. They have no trouble finding visas and work permits, and their jobs are extremely well-paid.
• Low-skilled workers: Rather than being handpicked, they migrate of their own volition, in order to work on complimentary jobs such as being janitors, retail workers, costumer service representatives and agricultural laborers. Oftentimes, they overextend their visas or do not have visas at all.

The dual labor market theory posits that low-skilled workers, with an irregular migration status, contribute to both economic and political nefarious purposes. On the one hand, irregular migrants are vulnerable to the abuses of their employers: for example, excessive working hours, wage thefts, unsafe working conditions, physical and verbal violence and debt slavery. These migrants form a docile working force that can be exploited in order to maximize profits. On the other hand, certain politicians also benefit from the existence of irregular migrants in a country. These migrants can be portrayed as scapegoats for bad economic conditions and can be subjected to xenophobic attacks, often facilitating the rise of far-right parties that promise to clamp down on migration.

In the Arab states of the Persian Golf, for instance, the Kafala system is used to monitor migrant laborers working in the construction sector and in domestic housekeeping. These workers are routinely subjected to exploitative working conditions bordering on slavery, because their migration status is contingent upon the wishes of their respective employers. As a general rule, foreign laborers in these countries have little chance of a prosperous life — but many prefer this fate instead of the even worse standards of living in their original countries.

New Economics of Labor Migration (NELM) Theory

The NELM theory of migration emerged in the late 1970s, thanks to the studies of scholars such as Oded Stark. This perspective argues that the decision to migrate is not taken by individuals, but rather by families. It is a theory with ties to anthropology and sociology, in that it discusses how the poor proactively try to improve their lives, even in the face of inequalities adversities. According to the proponents of the NELM theory, there are various reasons that make a family make the decision to migrate:

• Migration is a way to diversify the work of the members of the family, so that a crisis in a given place or economic sector will not make all relatives worse off. Thus, people might migrate even if it means not increasing their salaries — after all, just diversifying sources of income might be valuable.
• Migration is a way to help family members raise enough money to sustain the family business. Accordingly, many migrants who move to well-paid jobs in other regions send remittances back home. In countries such as Tajikistan, in Central Asia, and Tonga, a small island in the Pacific, remittances account for almost half of the gross domestic product (GDP).
• Migration is a way to deal with relative deprivation: the circumstance in which a family has enough money to move elsewhere, and knows that, in doing so, the prospects for the family are likely to improve.

NELM theories have been criticized because they see families as a “black box” — meaning that they neglect the dynamics that take place within each family. For instance, migration might be a way for children to gain independence from their fathers, or for women to escape from abusive husbands. Also, in some cases, families might split apart because elders are unwilling to leave their homes while younger people wish to find better jobs in a different place.

Diaspora theory

As a general rule, a diaspora is a population that has become scattered around the world after being displaced by force — such as African slaves who were sent to American and Asian colonies and Jews who fled Nazi Germany. Nowadays, in ordinary speech, a diaspora refers to any transnational community that shares certain characteristics, which were described by South-African sociologist Robin Cohen, in the book Global Diasporas:

• The community is present in many different states.
• The community migrated either by force or in search of business or colonial opportunities.
• The members of the community share a certain collective memory.
• Within each foreign country, the members of the community share a sense of solidarity among themselves and engage in communal activities.

According to the proponents of the diaspora theory, such as Alejandro Portes, a diaspora emerges either from the encouragement of governments and colonial companies or from the encouragement of migrants themselves. However, authors such as Luis Eduardo Guarnizo have claimed that diasporas initiated by migrants themselves are rare, and that relations between members of a diaspora are greater within privileged classes.

Migration Network Theory

The migration network theory focuses on the interactions between migrants within a region and between them and those who remained in the source regions. This perspective proposes that migration from one region to another begins due to a structural factor, but that it is perpetuated thanks to the emergence of migratory networks. For example, a rise in unemployment or a natural disaster might lead people to look for another place to call home, and their presence elsewhere might give rise to a migratory network that incentivizes others to migrate and reduces costs and risks involved in doing so.

In developed countries such as the United States and those that form the European Union, it is not unusual to see experienced migrants helping out recently-arrived migrants in finding a home, applying for jobs, opening a bank account and even dealing with bureaucratic procedures. Also, experienced migrants may be asked to invite new workers to their workplaces, in order to meet growing demand for labor. Furthermore, there are migratory networks that are created and/or maintained by specialized companies that offer services for migrants, such as facilitating visas — they are known as the “migration industry”. All of these cases highlight the impact of network effects on migration.

Migration Systems Theory

While many, if not most, migration theories emphasize the consequences of migration for destination regions, the migration systems theory looks at the reciprocal effects that migrants produce in places of origin and destination.

In 1970, Nigerian geographer Akin Mabogunje presented a comprehensive study of rural-urban migration in Africa, but his ideas can also be extrapolated for understanding international migration. He believed that migrants, when being welcomed and finding a better life elsewhere, reported these good news to the friends and relatives who stayed behind in their places of origin. According to him, the flow of positive information from destinations to origins makes more people want to migrate. Furthermore, these people are certainly not wanting to migrate to anywhere, but rather to specific places that are considered the best.

Other authors have elaborated on Mabogunje’s ideas, particularly two American sociologists. According to Peggy Levitt, migrants generate the so-called “social remittances” — flows of ideas and identities that arrive in certain regions and change people’s aspirations. Ultimately, she claimed, people would no longer be satisfied with their current lives, because there are better lives elsewhere. Likewise, Douglas Massey used the concept of “cumulative causation” to argue that migration engenders socioeconomic changes in places of origin. He believed that, if migrants were successful in their ventures, a “culture of migration” would emerge and more and more people would want to migrate. The central argument of migration systems theory is that a certain flow from one region to another might bring about other flows, in both directions.

The main issue with these theories is that they fail to account for the rise and the decline of migration systems. For example, most initial migrations from one place to another do not lead to the creation of migratory systems, such as those that are made by nomads. In addition, some consolidated migration routes might decline, such as those that involved exploiting natural resources that have been depleted. A case in point are the flows between mining towns and port towns, which commonly become less intense as mineral reserves are exhausted.

Another issue is that these theories neglect the negative aspects of migration systems, which might be exclusivist or not be positive at all. Certain Cuban communities in the United States, for example, are loath to welcome supporters of the Communist regime that rules their homeland. These people are actively discriminated against in terms of job offers in the informal economy. Besides that, migrants in general might be unwilling to support other migrants — after all, all of them compete against one another for jobs, residences, and even government support in terms of relief aid and regularization of migratory status.

Migration Transition Theory

In 1971, American geographer Wilbur Zelinsky introduced the migration transition theory, under the influence of the demographic transition theory by Warren Thompson. This approach contends that the intensity of migration is related to the level of development within a certain region. In simple terms, there are the following phases of migration, with changes in its patterns over time:

• In premodern societies, which are those that have not urbanized yet, there is little to no migration. People are used to living always in the same place, and there is little hope for anything else, because communication and transportation networks are still inadequate for migration.
• In early transitional societies, which are those that are beginning to urbanize, migration increases substantially. People suddenly have to deal with population growth, the reduction in rural jobs, and the technological development. Because of this, there occurs a massive movement of people from the countryside to the cities.
• In late transitional societies, which are those in which cities are more prominent than rural areas, urban-urban migration increases while rural-urban migration decreases. At this phase, there are many cities competing with one another to attract the labor force, and only a few people remain in the countryside in order to support agriculture and livestock farming.
• In advanced and in super-advanced societies, nearly all migration is urban, and there is much more immigration than emigration. People who live in such societies are not willing to move elsewhere, while people from less developed regions are more than eager to migrate to a better place.

On the one hand, the migration transition theory has been empirically validated multiple times — that is to say, there is abundant evidence that migration (particularly immigration) increases in tandem with economic development. For instance, according to the World Bank, the countries that receive the most migrants are those in the process of developing — especially because developed countries place obstacles to migration. On the other hand, advocates of this theory must keep in mind that the correlation between migration and development is neither inevitable nor irreversible. Lebanon’s capital Beirut, for example, was regarded as the “Paris of the East” because it was a great place to live, but all changed when the country found itself ravaged by war and political instability in the second half of the twentieth century.

Conclusion

Theories of migration have emerged with a clear purpose: to help explaining why people decide to leave their homes and try to settle in another place. Originally, it was believed that people migrate because places have attributes that either make them want to live there, or want to live elsewhere — for instance, different labor markets. In the 1970s and 1980s, certain theorists viewed migration as a consequence of systemic interactions within the capitalist system — notably, interactions that reinforce global inequalities because they mainly affect extremely low-paid and high-paid workers. More recently, scholars have come to the conclusion that social factors are crucial to explain migration. The NELM theory concentrates on the reasons for a family to migrate, while the diaspora theory and the theories about migration networks and systems focus on the role of society as a whole. All of these perspectives are required for thoroughly understanding why migration happens and the ways it can be fostered.