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Scotland's Population 2001: The Registrar General's Annual Review of Demographic Trends

CHAPTER 5 – MIGRATION

In addition to births and deaths, migration is the other component of population change. However, unlike births and deaths, there is no comprehensive source for estimating migration and hence it is the most difficult component of change to measure. Migration and the reasons for migrating are also much more susceptible to short term changes in social and economic circumstances than births and deaths. These factors and the fluctuating nature of migration make it very difficult to estimate.

Patterns of migration tend to vary according to age. Generally, longer distance migration is more common amongst young people between the ages of 20 and 35, with particular implications for changes in the labour force and population of working age. Regular information on the other characteristics of migrants (for example, educational qualifications, country of birth and ethnic group) is limited, although more will become available when the detailed results from the 2001 Census are published next year.

There are many reasons for migrating and the factors tend to vary according to whether the movement is over a relatively short distance (e.g. from a city to its surrounding area) or over a longer distance (eg. away from Scotland altogether). Particularly in the case of longer distance migration, it is often sensible when trying to understand migration to consider both push and pull factors relating to the area of origin and the area of destination. Push factors in some overseas countries may include unemployment, famine, persecution or war, all of which may drive people to leave their home for a new country. Similarly, there may be pull factors which attract people to a country such as a prosperous economy, quality of life, or favourable immigration laws.

Trends in migration since 1951

Estimates of net migration to and from Scotland since 1951 are shown in Figure 5.1. Historically, Scotland has tended to be a country of net out-migration rather than net in-migration, that is more people leave Scotland to live elsewhere than move to live in Scotland. However, since the 1960s the level of net out-migration, some 30,000–40,000 a year, has reduced significantly and in recent years has been less than half of the peak net migration losses in the 1960s. Indeed, in some years during the late 1980s and early 1990s, and again in the most recent period, Scotland has sometimes experienced net migration gain rather than loss. As can be seen from Figure 5.1, there has been an underlying, long-term, trend of decreasing net emigration from Scotland over the last 50 years.

It should be noted that estimates of net migration are the difference between much larger gross flows of migrants into and out of Scotland. In the last ten years these have typically been of the order of 70,000 both in and out of Scotland. The level of net migration can be significantly affected by relatively small changes in these gross flows from year to year, particularly if one flow rises while the other falls.

Migration to and from Scotland comprises moves to/from the rest of the United Kingdom and moves to/from the rest of the world. In net terms, the contribution to the overall total of moves with the rest of the UK and with countries overseas is roughly similar. This broad relationship has been maintained over the last 50 years, and the net loss from Scotland has reduced since the 1960s and early 1970s both in relation to the rest of the UK and the rest of the world (Figure 5.2). The exception to this trend occurred in the late 1980s and early 1990s when there was a net surplus of moves into Scotland from the rest of the UK, but a net loss of migrants overseas.

Figure 5.1 Estimated net migration, Scotland, 1951–2001

Figure 5.1 Estimated net migration, Scotland, 1951–2001

Figure 5.2 Estimated net migration, moves to/from the rest of the UK and overseas, Scotland 1951–2001

Figure 5.2 Estimated net migration, moves to/from the rest of the UK and overseas, Scotland 1951–2001

Migration by age and sex

The age/sex pattern of migrants tends to remain relatively constant from year to year. Figure 5.3 illustrates the age/sex distribution of migrants for males and females moving into and out of Scotland from the rest of the UK between 2000 and 2001. The peak ages for migrating are early to mid-twenties reflecting moves out of the parental home to attend higher education or take up employment. There also tend to be smaller peaks for moves of the very young, under the age of five. This reflects migration of parents who move home before their children have started school. The pattern of migration is very similar for men and women though women tend to have much larger peaks in their early twenties than men. This may reflect different patterns of re-registering with an NHS doctor after a move rather than different patterns of migration.

Figure 5.3 Movements between Scotland and the rest of the UK, by age, mid 2000 – mid 2001

Figure 5.3 Movements between Scotland and the rest of the UK, by age, mid 2000 – mid 2001

Source: NHSCR

The peaks in migration for males and females in their early twenties create marked net migration gains at ages 19 and 20, and net migration losses at ages 23 and 24. These patterns are consistent with an influx of students from the rest of the UK starting higher education followed by a return to elsewhere in the UK after completing their education.

A similar age/sex pattern of migration occurs within Scotland between Health Board areas (Figure 5.4), with peak ages occurring in the late teens and early twenties for both males and females. Apart from Census data there has been no reliable source of information on moves between smaller geographical areas.

Figure 5.4 Moves between Health Board areas within Scotland, by age and sex, mid 2000 – mid 2001

Figure 5.4 Moves between Health Board areas within Scotland, by age and sex, mid 2000 – mid 2001

Source: NHSCR

Scale of migration

The estimated number of migration moves over the last twenty years is shown in Figure 5.5 distinguishing moves between Health Boards within Scotland, cross-border moves to/from the rest of the UK, and moves to/from the rest of the world. These figures are subject to revision following the results of the 2001 Census but still provide a good indicator for comparing the relative size and trends of different flows.

The relative size of the flows within Scotland, between Scotland and the rest of the UK, and between Scotland and the rest of the world, has remained similar. The majority of moves are shorter distance moves within Scotland at about 80,000 a year. Regular information is only available for moves between Health Board areas, and if information were available for moves within Health Board areas we would expect an even larger number of moves within Scotland. The majority of people who move home or residence do so within a very short distance. Generally, the scale of movement decreases with the distance of the move.

Figure 5.5 Movements between Health Board areas within Scotland, to/from the rest of the UK and to/from the rest of the world, 1981–2001

Figure 5.5 Movements between Health Board areas within Scotland, to/from the rest of the UK and to/from the rest of the world, 1981–2001

Migration and the distribution of population within Scotland

Migration has a large impact on population distribution within Scotland and is often, at local level, the most important component of population change. Net migration rates, that is the amount of net migration between 1991 and 2001 as a proportion of the 1991 population, are a useful indicator when comparing migration between areas of different sizes. The available information on net migration rates for Health Board areas is shown in Figure 5.6. Although the figures use migration estimates based on the existing, or unrevised, population series for the 1990s, the relative pattern for different areas is unlikely to change once account has been taken of the 2001 Census results.

Generally, areas in the south, east and north of mainland Scotland have experienced migration gains over the last ten years (indicated by a positive rate in the chart), with the largest relative gain taking place in the Borders (50 migrants per 1,000 population). In contrast, nearly all of the migration loss was in the west of Scotland with the largest relative rate of migration loss (-71 migrants per 1,000 population) in Greater Glasgow. For comparison, the rate of migration loss for Scotland as a whole over the period was 7 migrants per 1,000 population.

Figure 5.6 Net migration rates per 1,000 population for Health Board areas, 1991–2001

Figure 5.6 Net migration rates per 1,000 population for Health Board areas, 1991–2001

Estimating migration

Migration is the most difficult component of population change to estimate. The other components of population change (births and deaths) are estimated using data from the civil registration system, which is considered to be virtually complete and therefore easy to estimate. In contrast, there is no comprehensive system which registers migration in the UK, either moves to or from the rest of the world, or moves within the UK. Estimates of migration therefore have to be based on survey data and the best proxy data that exist.

Sources of data for estimating migration

Migration is derived from two key sources of data: The International Passenger Survey (IPS) for moves into and out of Scotland from outside the UK, and the National Health Service Central Register (NHSCR) for moves between Health Board areas within the UK. There is no comprehensive source for estimating migration for areas below Health Board area and changes in data sources such as the electoral and school roll have been used to derive migration at Council area level.

The IPS is a continuous voluntary sample survey conducted by the Office for National Statistics at the principal air, sea and channel tunnel routes between the UK and countries outside the British Isles. The sample of migrants contacted within the survey is small, particularly for Scottish migrants, and therefore estimates derived from the IPS are subject to larger sampling and non-sampling errors, and are considered less reliable than UK level estimates. Information about the country of origin and destination, and age of migrants is particularly subject to error.

The NHSCR records the movements of patients between NHS General Practitioner areas in the UK. Each time a patient transfers to a new NHS doctor in a different Health Board the NHSCR is notified and this is considered a migration move. Counts of these re-registrations are used as proxy indicators for moves within the UK and account for about 70 per cent of all migration movements into and out of Scotland.

Quality of migration estimates

As noted in the population chapter, the results of the 2001 Census for Scotland were some 50,000 lower than the previously published mid-2000 population estimate. This difference is considered to reflect cumulative errors in the previous estimates of young male migration during the 1980s and 1990s, in particular a likely underestimation of young male migration from Scotland to the rest of the world during this period. To the extent that moves from Scotland to the rest of the UK may have been under-recorded, the implied increase in overseas migration would be less.

More information on the cumulative migration error since 1981 can be found in the GROS Paper Comparisons with Previous Estimates and Implications for Revisions on the GROS website (www.nrscotland.gov.uk) or by contacting GROS Customer Services.

Improving future migration estimates

A number of initiatives are under way or planned with a view to improving future estimates of migration. These include:

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