In my migration studies the theory that I liked (loved, actually) the best was migration systems theory. I thought it captured the complexity and interdependence of migration in a wonderful way and one of my first papers was about the migration system that I thought existed between Quebec and France.
General systems theory goes back to the middle of the 20th century. Since then it's been applied to a lot of other fields. It argues that a system is a set of interconnecting elements that create a specific environment that is much greater than just the sum of its parts. In 1970 a fellow named Akin Mabogunje (a Nigerian professor of geography) applied systems theory to internal migration between rural and urban areas. And then it was applied more broadly to international migration.
What do I like about it? It's a more holistic approach In order to understand a migration flow you have to look at the whole picture: sending AND receiving countries and the links between them be they formal or informal, economic or cultural. In migration systems theory people are just one element among many others and it's the interaction of the elements and the creation and maintenance of links that make up the system. Furthermore, the history of those connections matter a lot; with Quebec and France I went back 400 years and traced the always evolving links to the present day.
Evolution is the key word here. Systems are dynamic in the sense that elements in it change and so do the links. The demographics of Mexico, for example, or the strained circumstances of Americans on fixed incomes will change the migration system between those two countries. The thirst for native English speaking teachers in Japan could change as could the number of Anglophones from the US, Canada, or Great Britain with university degrees willing to migrate and provide that service. Culture, science and economic ties matter, too. In the 18th and 19th centuries, Americans came to France and Germany to study medicine. In 17th century French urban dwellers went to Canada to become farmers. In the 21st century migration system between France and Quebec a common language is still a driver of reciprocal migration between the two - a good example of how migration between two developed countries (sometimes called north-north migration) has elements very similar to migration between developed and less developed countries.
In 1989 James Fawcett published a very good paper that attempted to define the basic elements of a migration system. He identified four categories of linkages: State to State Relations, Mass Culture Connections, Family/Personal Networks and Migrant Agency Activities. A Mass Culture connection could be a common language or history. State-to-state relations could be formal agreements to recognize each others professional and academic credentials. Networks of people are another type of link where, for example, one person migrates because of marriage and other members of the family follow. The most interesting to me are the Migrant Agency Activities which still exist and not just in the Philippines. I think many Americans, Canadians and others would be very surprised to learn that Japanese companies in the education industry have a presence in countries outside of Japan and recruit young college graduates in major cities. ECC. a language school in Japan is actively recruiting now in Australia, Canada, the US, and the UK. This is an important, though often overlooked, migrant recruitment that is very active and drives temporary and permanent migration from Anglophone countries to Japan.
I find that migration systems theory is a very elegant and comprehensive way of looking at migration flows. For instance, with a systems approach to migration between the US and Mexico would look at all the links between the two and what is happening in Mexico is just as important as what is happening in the US. It would consider how the flows are reciprocal: Americans migrating to Mexico, for example, as well as Mexican nationals coming to the US. These flow are not disconnected from each other or from the other cultural or economic links. With that in mind, many migration flows look more like an exchange of people as opposed to a unilateral exodus. Granted, one flow may be numerically greater than the other but they are still linked and in very interesting ways.
On a personal level all of us who live outside of our countries of origin can use this theory to start asking a different, much broader question then the usual "Why I moved to [insert country here]." The better question is: How do I fit into this broader migration system between Canada and Japan, the US and France, Mexico and Spain or any other combination of countries? An American academic, for example, in Japan will find there is a long history in Japan of importing foreign academics. He/she might also learn that US citizens do not pay a fee for getting a Japanese visa (State to State agreement). The contract and terms under which a foreigner was recruited for the position is a Migrant Agency Activity. The position itself may be known to him or her because of a personal and academic network. And it may be (something to investigate) that this migration system was kicked off (or perhaps only greatly encouraged) by war and occupation, though it is not sustained by these things today.
Now I am not saying that there actually are migrations systems between the countries I have mentioned - that argument would require much more research than I have done in this short blog post. However, I invite you to consider your own migration experience in light of the links between your home and host country and to consider how your own migration may have been facilitated and shaped by being part of a larger system. It was quite a revelation to me, for example, how a sister city association between Nantes, France and Seattle, USA was the French/American link that led to my own migration to France. So follow the links and see where they take you.
The truly fascinating aspect of migration system theory for me is that "[e]ach migration system is unique in the sense that the combinations of links between two countries will be different from one migration system to another." (Quebec and France - A Dynamic International Migration System by V. Ferauge, 2016.) That means that every migration system can be analyzed by its links but when they are taken together every migration system will be singular. For that matter, individual migration experiences are, I argue, a result of different links in different contexts which makes comparisons between migrants and flows possible, but also allows each migrant to be unique thanks to different combinations of links as well as different personal life trajectories and levels of social or economic capital. This, I find, is quite familiar to me in that it very closely resembles Amin Maalouf's take on identity and individuality: "Thanks to all my adherences, taken separately, I have a certain relationship with a large number of people like me; thanks to the same elements, taken all together, I have my own identity, which can never be confused with any other."