ANNEX: MIGRATION BETWEEN DEVELOPING COUNTRIES
AND THE UK (continued)
Background notes on International Migration
Statistics
1. A migrant is defined as someone who changes his
or her country of usual residence for a period of at least a year,
so that the country of destination effectively becomes the country
of usual residence.
2. The international migration estimates are compiled
from three main sources of migration data:
- the International Passenger Survey (IPS);
- Home Office data on asylum seekers and their
dependants; and
- estimates of migration between the UK and the
Irish Republic.
3. The International Passenger Survey (IPS) is a
continuous voluntary sample survey conducted by the Office for
National Statistics. It covers the principal air, sea and Channel
Tunnel routes between the UK and countries outside the British
Isles. Routes between Channel Islands/Isle of Man and the rest
of the world are excluded, as is all movement of diplomats and
armed forces personnel.
4. The estimates of total international migration
for 1991 to 2001 were revised in the light of the 2001 Census
results which showed that the net inflow of international migrants
to the UK had been overestimated over the previous decade. Details
of the revised methodology can be found at Appendix B of the most
recent edition of the annual reference volume for international
migration. The 2001 annual reference volume can be found on the
National Statistics website at the following address:
. http://www.statistics.gov.uk/downloads/theme_population/MN28.pdf.
5. A National Statistics Quality Review of international
migration statistics was initiated in March 2002. This was aimed
at identifying the means of making the required improvements
to the reliability and comprehensiveness of international migration
statistics. The Review was published on 2 September 2003. An implementation
plan detailing how the recommendations will be taken forward is
also available. Both the report and the plan can be found at the
link shown below. . http://www.statistics.gov.uk/methods_quality/quality_review/population.asp
The Office for National Statistics (ONS) note that
"these estimates should be considered as a rough guide only
and should be interpreted with caution, as some of the components
of international migration are not calculated using ONS' published
methodology. Apportionment of published figures by geographic
areas has been used where necessary."
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