Measuring international migration in Asia

ABSTRACT

The benefits of having consistent and complete information on migration flows within, from and to Asia are numerous and worth the investment. They include a much better understanding of how migrants are responding to economic developments across Asia and how they are transforming both origin and destination societies. The challenges to producing international migration flow statistics in Asia, however, are immense. Hardly any countries provide data, and for those countries that do, they are often incomplete or incomparable with other countries' measures of migration. In order to produce comparable statistics on migration flows and immigrant population stocks, one needs a range of data sources and estimation strategies.

KEYWORDS:

• International migration

International migration is necessary for understanding many of the demographic, economic and social changes that are occurring in Asia, including for example population growth, employment, educational obtainment, and social cohesion amongst immigrant groups. Evidence from census information on immigrant populations indicates international migration is increasing in the region and becoming more influential as a factor of change (Abel et al., 2019ø Charles-Edwards et al., 2016; De Haas et al., 2020; Hugo, 2005). However, without actual statistics on the movements, it is difficult to understand what is driving the change or even how many persons are migrating across countries in any given year. Further, the absence of this information greatly hinders policy formation and planning by government and international agencies in the region (Huguet, 2008).

The challenges to producing international migration flow statistics in Asia are immense. Hardly any countries provide data, and for those countries that do, they are often incomplete or incomparable with other countries’ measures of migration (Raymer et al., 2022). Most of what we know about global migration is based on immigrant population stock data from censuses gathered once every five or ten years, and experiences from major receiving countries consisting primarily of Western countries in Europe, North America and Oceania. Further, immigrant population stock data, which currently represent the best information available for studying migration in Asia, do not translate well into flows. Stocks are based on birthplace or citizenship and, thus, fail to capture the large return (counter-flow) movements, as well as undocumented and temporary visa movements (Hugo, 2005). They also represent a net accumulation of flows over time, and since origins of migration tend to evolve over time, they can misrepresent actual movements, especially for countries with ageing immigrant populations.

Understanding international migration within Asia, as well as from and to other regions in the world requires information on the numbers of persons moving from one country to another during a specific period of time – information we do not have. Due to the region’s population size alone, 4.7 billion persons in 2022 out of 8.0 billion (United Nations, 2022), the numbers of migrants crossing borders within, from and to the region are undoubtedly influencing the social and economic conditions both in the origin and destination societies. Indeed, according to the United Nations International Migrant Stock Database, it is estimated in 2020 that 281 million persons were living outside their country of birth with 86 million living in Asia and 115 million originating from Asia (United Nations, 2020).

Ideally, measures of migration flows and stocks would be aligned, as recently proposed by the United Nations Expert Group on Migration Statistics. In their conceptual framework report (United Nations, 2020b), international migration is defined as the movement from one country to another that results in a change in the country of usual residence. Thus, migration is distinguished from other types of international moves of shorter duration, such as cross-border workers, seasonal labourers or tourists. Measuring shorter duration international moves are also important but should be treated separately. The reason is that information on the numbers of persons changing their country of residence are needed for purposes related to population planning and policy in both the sending country and receiving country. Another advantage of measuring international migration as a change of residence is clarity over the measurement. So long as countries are transparent in their rules of residence, then migration can be defined accordingly and, for international comparisons, may be later harmonised using statistical models (see, e.g. Raymer et al., 2013).

Another key component of the conceptual framework proposed by the United Nations Expert Group on Migration Statistics (United Nations, 2020b) is the disaggregation of migrant stocks and migration flows into four resident subgroups. These four groups are native-born citizens, native-born foreign citizens, foreign-born citizens and foreign-born foreign citizens. They capture the intersection between the two main types of immigrant population stock data that are available across countries, i.e. foreign-born status and foreign-citizen status. Immigrants defined as persons born outside the country of interest have the advantage of consistent definition over time. The timing of when the migration occurred is unknown, however. Immigrants defined as persons without citizenship of the country of interest are useful for knowing the numbers of persons who have limited access to services and protections. If these persons become citizens, however, their migrant status disappears and from a data perspective, one does not know whether they emigrated or became citizens. Also, in some situations, persons can be citizens even though they have never lived in the country, for example, by being born to citizens living abroad. Alternatively, persons may be born in the country but remain foreign citizens if, say, their parents are both foreign citizens. In summary, the four sub-population groups provide a pragmatic means to have a much better understanding of both migrant stocks and flows because they capture the intersection between the two main types of migrant information often gathered by both general purpose and administrative data sources: country of birth and citizenship.

In order to produce the statistics on migration flows and immigrant population stocks, as described above, one needs a range of data sources. Resident populations are most commonly measured using censuses and then updated with registers on births, deaths and international migration. If no information on international migration flows is available or accessible, net international migration may be inferred as a residual using the demographic accounting equation. However, this approach is not ideal as the residual term used to approximate net international migration may contain errors in the measurement of populations, births or deaths. Ideally, both immigration and emigration would be measured using administrative data sources related to population registers or border crossings. However, this requires considerable sophistication in data management and many countries in Asia have yet to develop such systems.

Asia is undergoing rapid economic development with many countries already exhibiting low fertility and high longevity (Zhao & Hayes, 2018). Migration theory based largely on European experiences posits that as countries economically develop, they experience increased emigration which gradually decreases to the point where it becomes lower than immigration. That is, immigration becomes increasingly important as a country develops in order to maintain economic development by bringing in both high skilled and low skilled labour. Asia contains many countries that have experienced greatly increased Gross Domestic Product values over the past several decades, most notably China. Whether China will soon be recruiting large numbers of immigrants to support its growing economy and ageing population is debatable. Nonetheless, China’s role as a major sender of migrants is likely to change over the next couple of decades. Moreover, there are still many large and growing populations in Asia that are likely to exhibit higher levels emigration alongside their growing populations and economies, including, for example, Bangladesh, India, Indonesia, Pakistan, Philippines and Vietnam.

Knowing how many people are emigrating or immigrating each year is a starting point for understanding the mechanisms of migration. Following this, details are needed on the origins, destinations, ages and gender (sex) of migrants. Together, these characteristics provide the basis for understanding both the motives and consequences of migration. They also provide the context for other analyses of migration related especially to the Global Compact on Migration (United Nations, 2019), including those concerning migrant wellbeing, migrant labour, integration, and policy objectives.

The benefits of having consistent and complete information on migration flows within, from and to Asia are numerous and worth the investment. They include a much better understanding of how migrants are responding to economic developments across Asia and how they are transforming both origin and destination societies. Also, as countries are connected together through migrants’ motivations for seeking labour, human capital or reunion with family members, we can learn more about different types of migration occurring in the region. Finally, at the international level, we could determine the influence that countries in Asia have towards global migration patterns, as well as how they are likely to evolve over time.

Disclosure statement

No potential conflict of interest was reported by the author(s).