Memorandum by the Statistics Commission
This submission sets out the views of the Statistics
Commission in relation to question 13 in the Committee's Call
for Evidence:
"How can data on immigration be improved?
What improvements are already being put in place? To what extent
have `inadequate data' affected public policy? How confident can
we be in forecasts of future immigration and how important is
it that such forecasts are accurate?"
The Statistics Commission was set up in 2000
to "help ensure that official statistics are trustworthy
and responsive to public needs", to "give independent,
reliable and relevant advice" and by so doing to "provide
an additional safeguard on the quality and integrity" of
official statistics. It operates openly and independently, with
all its papers normally available publicly.
How can data on immigration be improved? What
improvements are already being put in place?
1. The available statistical information
about immigration into the UK (and migration within the UK and
emigration from the UK) is weak, particularly statistics for areas
with large migrant populations. The Statistics Commission has
been pressing for improvements to migration statistics for some
years. Our 2003 report The 2001 Census in Westminster contained
a recommendation that "the quality of migration data should
be addressed with urgency" and noted that the solution "might
involve major changes in administrative practice" and that
"statistical surveys are unlikely to be adequate". This
position was repeated in subsequent reports.
2. There is currently no satisfactory source
which can provide the raw information, at national and local levels,
that is required for statistical purposes. Sample surveys, of
the kind typically carried out by statistical offices, are not
the answer. Only the decennial Census currently has the potential
to offer relatively reliable information on population at a local
level. The Census acts as a baseline for subsequent years' population
estimates. But these estimates become increasingly unreliable
in the latter years of the decade.
3. A "National Statistics Quality Review
of International Migration Statistics" in 2003 made recommendations
for improving both the estimation of total migration flows to
and from the UK, and the allocation of international migration
to local areas. Whilst we understand that some progress has been
made since 2003, it is also clear that more will need to be done.
4. In December 2006, the Office for National
Statistics published the report of the Inter-Departmental Task
Force on Migration Statistics which recognised that major improvements
were needed and set out a long-term programme for change. The
Statistics Commission believes that this report presents substantially
the right path ahead but we would like to see a commitment from
Government that it will fund and pursue the necessary work—much
of which falls to departments other than ONS. To date we are not
aware of a Ministerial commitment of this kind.
5. In January 2007, ONS published a report
looking into the feasibility of estimates of short-term migration,
and published feedback on this in April. We understand that they
expect to produce a set of national level estimates in the Autumn
2007 and at local area level in 2008. Short-term migration is
important as it is not normally included in the official figures
for migrants (which only counts "migrants" as those
intending to stay for more than a year) but can have significant
implications for local services.
6. In April 2007, ONS released information
on changes in the way migration will be estimated for the mid
year estimates from 2007 onwards. However, this largely applies
new methods to existing sources which have known weaknesses. A
number of local authorities have expressed concerns about this
approach.
7. ONS has also carried out research directly
with some local authorities to evaluate local population estimates
using various local and national sources of information—and
has recently published a review of the potential use of some administrative
sources in relation to making population estimates.[53]
8. However, we think that more local area
research, particularly to evaluate official estimates against
several administrative sources of information in the most problematic
areas, should be carried out and published by government. ONS
cannot, of course, "negotiate" local population figures;
such estimates must all be produced in the same systematic way.
The aim would instead be to get a better understanding of the
scale, geographical variability and distribution of the problems
with population and migration estimates.
To what extent have "inadequate data"
affected public policy?
9. It is important to have good quality
statistics on migration and the population, for policy development
and for planning and providing public services. In 2006, the Statistics
Commission set out in a letter[54]
to several Ministers the consequences of not having adequate data
in this area:
— Weak data on migration can lead to
inefficiency in the allocation of grants to local authorities,
the NHS and other public services. .., some £100 billion
a year is being distributed through formulae that are directly
affected by migration estimates. We are not in a position to estimate
the cost to the public purse.. but it could be very substantial.
— Mis-measurement of migration could
contribute to failure to predict accurately the demand for services
from the NHS, in education, social services, etc. Over-provision
for such services is wasteful of public money; under-provision
is liable to lead to unnecessary suffering. There could also be
longer-term consequences in relation to the planning of social
housing and other infrastructure.
— The development of policy on immigration,
monitoring the impact of current policies, and the provision of
services targeted at immigrant communities may all be adversely
affected by weak data.
— The 2011 Census may be left vulnerable
if the migration estimates in the years prior to 2011 are not
robust. Essentially, the danger is that if the Census appears
to contradict earlier estimates, as happened in 2001 in some cases,
there will be a loss of confidence in the utility of the census
data.
10. The official responses to that letter
were essentially that the Government recognised the need to do
more but no specific commitments were made.
11. The Commission also wrote, in 2006,
to the then Minister for Local Government urging Whitehall departments
to take a lead in finding a solution to the problem of measuring
internal and international migration. In his reply, the Minister
stressed the Department's support for the Inter-departmental Task
Force on Migration Statistics set up by ONS and the Improving
Migration and Population Statistics (IMPS) research programme—though
did not make any specific commitment to undertake any work within
DCLG itself.
12. More recently (17 May 2007) I wrote
to the Times stressing that what is needed is a sound administrative
system for recording numbers of people entering the country and
their immediate and subsequent destinations and that it is impossible
for ONS to produce the desired answers on their own.
13. Much more work is going to be needed
to develop new sources of data to achieve better estimates. We
have argued that to produce better estimates, ONS will need to
receive raw information on people moving into and around the country
from the big Whitehall departments: the Home Office, the Department
for Work and Pensions, the Department of Communities and Local
Government, HM Revenue and Customs, and the Department of Health
among others. It is impossible for ONS to produce the desired
answers on their own; we have observed some reluctance on the
part of departments to develop and share information for such
purposes and we believe this will need to be resolved among Ministers.
14. There are of course important technical
and data protection implications in bringing all the necessary
information together; any data on individuals would have to be
kept totally confidential. The Statistics and Registration Service
Act 2007 which received Royal Assent in July contains provisions
that might ease some of the barriers to the statistical use of
administrative data in order to create better migration data.
15. The Audit Commission recently recommended
more joint working between local and national government, such
as sharing data on National Insurance numbers issued.[55]
We would support any initiative of this type.
16. There are no quick or cost-free answers.
Government needs to decide whether the issue is of sufficient
importance to justify the commitment of substantial resources
to address the technical issues and statutory obstacles. Other
countries have solved the problem through the use of integrated
population and household registers. There is no reason why the
UK could not do the same given time and resources.
17. In the short term, there is a good opportunity
to carry out a major experiment of how well existing administrative
data held by various government departments (notably the Department
for Work and Pensions) could be used to build not only an "administrative
census" but also to give arguably much better estimates of
migration. If this were done and the results compared with the
real census, we would have a much better idea of whether we can
get reliable, frequent and up-to-date population and migration
figures from administrative source data. This may however require
secondary legislation under the Statistics and Registration Service
Act. We think the case for developing an approach based on administrative
data is overwhelming (subject of course to complete confidentiality
being preserved and the data only being used for these statistical
purposes). We understand that currently academic researchers are
allowed confidential access to the extensive and rich DWP database
whilst ONS is not. This seems indefensible given the importance
of population and migration data to public policy.
28 September 2007
53 http://www.statistics.gov.uk/about/data/methodology/specific/population/future/imps/updates/downloads/admin.pdf Back
54
Statistics of International and Internal Migration, letter to
the Minister of State at the Home Office and others, 8 May 2006. Back
55
Crossing borders-Responding to the local challenges of migrant
workers, Audit Commission, January 2007. Back
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