Examination of Witnesses (Questions 1-19)|
WEDNESDAY 24 OCTOBER 2001
1. Welcome back to the Committee and welcome
to our first inquiry of this Parliament which is into the Census.
For the convenience of the shorthand writer could you identify
yourself and your colleague.
(Mr Cook) I am Len Cook, National Statistician. John
Pullinger is Executive Director in ONS.
2. May we begin with a general question about
the 2001 Census? Were you generally happy with the way it was
conducted? Did it go to plan?
(Mr Cook) There are four really big issues
in a census which you have to get right. The first one is being
able to get an agreement on what should be in the Census and get
that agreement with Parliament, with the public in terms of the
acceptability, and Ministers. That was successful; we ended up
with a pretty good census form. The second is to be able to organise
a field force, to get the questionnaires out and get them back
in again. That went very well but it was hindered by the Post
Office. I can talk about that in terms of the variability of performance
of getting forms back from the Post Office, because we had a mail-back
census this time for the first time. The third is to find ways
of having everyone know about the Census, or nearly everyone,
before it actually happens, so there is a consistent measure of
trust across all different communities and regions. By and large
that was done very well. The Census communication campaign went
very well and the success of that was witnessed by the news media
coverage in the month or so around the Census, where by far the
overwhelming majority of criticisms about the Census were "Where's
my form?" not "Can you trust these people to run a census?"
and a lot of other issues. The fourth issue is about organising
a system to process the Census in a reasonable time. There are
two other issues. One is the ability to respond to events. We
had several very important and large events this Census. One was
the response to the ethnic question in Wales and that required
us essentially to think of ourselves as running a separate census
in Wales in terms of the communication programme compared with
England. The fact that in Wales the Census response rate was higher
than England in the end is testament to the success of that. The
second is foot-and-mouth disease. Basically we were able to carry
on with the Census despite the issues of foot and mouth. The third
issue was our Census helpline. We were literally swamped and within
three days we were able to fix that. My final comment is that
it is important to recognise that the Census in Britain on 29
April was carried out at a time when you could say we had a fair
wind behind us. If you think of the last couple of years, it was
really quite a positive and supportive time for a Census Office
to carry out a census in terms of the support of all communities
in Britain. I believe we captured the benefit of that fair wind
behind us in carrying out the Census.
3. Are you on track to produce the results next
(Mr Cook) As targeted, which is August next year for
summary results of the British population where the Census is
essentially used to update population estimates, produced only
in summary, age and sex for regions. Then at the end of the year
we shall have more detailed results of the key questions and then
in the first half of 2003, there will be the full set of Census
information released for the first time and once only.
4. Given you have computers and presumably these
forms are machine readable, why does it take two years to get
all this stuff out?
(Mr Cook) Because it is such a large Census. Sometimes
in Britain people tend to forget how big the country is. This
is an extremely large and complex Census questionnaire. We could
have done it faster if we were to invest more money up front.
We followed the scanning process adopted in the United States
Census by Lockheed Martin; we have adopted that methodology. We
have also chosen, through the one number Census, to use the Census
coverage survey to give us estimates of the undercoverage which
occurs in all censuses so that when we publish the results, it
will cover for those people who are not included in the Census.
Being able to put all that together has caused the time frame.
We could have produced some results earlier and then revised them.
But our consultations two and three years ago left us convinced
that that was what people actually wanted us to do.
5. I want to focus on one particular part of
the very helpful briefing document you sent out to us beforehand.
In the section about outputs you say, "The effort and expense
of taking a Census are worthwhile only when the results meet needs,
and are delivered effectively". I want to explore those two
points briefly. What are the needs that the Census meets? Why
go through this vast operation costing about £¼ billion?
(Mr Cook) We actually produce a wealth of information
from a whole range of statistical processes, statistical surveys,
administrative records which come from a lot of public processes.
The Census is the one data collection we have which embraces the
whole population, which tells us about each community, whether
we define it by region, by age, by ethnicity. It is the key benchmark
around which we are able to create other communities such as families,
people in localities. There is no other source of information
which gives us the opportunity to derive accurately communities
which we cannot measure directly. It is because of the value of
the Census that we can see changes not only in the totality of
the population, but in its structure. This means we can forecast
its change by knowing the changes in the age composition, the
family structure, the household formation of the population. We
can then produce reliable forecasts of the British population
for several decades ahead.
6. Could you not do that in any other way that
was cheaper? You could poll people, using various forms of other
market research which might give you a more cost effective solution.
Is there anything particular in the data you get out of this survey
that you could not get out in a different way?
(Mr Cook) Ultimately every sample survey we have,
whether it is a labour force survey, opinion polls, rests on having
something solid in terms of a measure of the population that it
is able to benchmark back to. For example, a large number of the
sample surveys we carry out in the UK are either benchmarked directly
to the 1991 population Census or population estimates we have
made since April 1991 that update those population measures. You
do need an anchor at some stage. We are seeing two important sources
of information becoming available to us now. One is a lot more
administrative records available to us through the computerisation
which is occurring in public agencies such as the Department of
Work and Pensions, where there is a very rich amount of statistical
analysis of the beneficiary population. That gives us almost 100
per cent of people in the youngest ages and it gives us a very
good measure of the population in the older ages. It does miss
out the population in the middle.
7. If we did not have the Census done, what
would be the major negative effects for public policies? What
information would we lack which would then create problems?
(Mr Cook) We would still have measures that count
the population in some way. In the United Kingdom we have very
good births and deaths certificates. Although we are an island
country, we do not operate as a police state at our borders and
it is very difficult to measure migration flows. In the last four
years some 70 per cent of the population change in Britain has
come from migration not from births and deaths. Our ability to
measure inter-censual population change accurately is limited
by our knowledge of migration flows.
8. Do any other advanced countries use any other
mechanism for finding this information, or in your view do all
of them use a census of this kind?
(Mr Cook) Some of the Nordic countries have ceased
having censuses because of their ability to integrate information
from a variety of public registers which exist. The one limitation
they find is that their ability to generate family and household
information is constrained solely by the knowledge that the state
has about families and households. They have very powerful registers
through tax, family benefits and other such processes.
9. May I explore the other part of this sentence
on the effectiveness with which you deliver the Census? The first
issue is one of cost. Am I right that this particular Census cost
about £¼ billion?
(Mr Cook) Yes.
10. Do you have any comparable figures for what
the cost is in other countries?
(Mr Cook) Yes, we do.
11. Do those demonstrate that we are particularly
cheap or not?
(Mr Cook) We are not particularly expensive and we
are not particularly cheap. We are considerably cheaper than we
were in 1991 and the per head cost in the United Kingdom is less
than that in Australia, for example.
(Mr Pullinger) I think it is less than in Australia
and the USA.
12. It is a bit unfair to ask you now, but would
it be possible to get some information from you on that?
(Mr Cook) Yes, we can provide that.
(Mr Pullinger) The reason we hesitate is that where
you have a situation as in the Nordic countries where you get
the same information from another source the cost comparison is
not straightforward. In the USA, they have a mix of a short form
and a long form designed to achieve slightly different ends. We
can certainly give you the costs. In a large number of countries
they are still doing traditional censuses in the same way we that
13. Obviously this information is only useful
and effective if it is fairly timely, otherwise things have moved
on. You did explain to the Chairman that the reason for it taking
so long to put together is because we are a large country. India,
United States are large countries as well. I am sure you have
very good reasons, but India completed their census results one
month after the census had been collected in; the United States
appears to be more like nine months. Compared with other countries
do we not seem to be quite leisurely about the way in which we
put together all of the information?
(Mr Cook) It is useful to look at a couple of things.
One is that we could have produced, as we have done in earlier
Censuses, based on simple counts of the Census forms, estimates
of the number of people in each area which would have been the
de facto population of people actually counted in a particular
area. What we are providing is the people who are normally resident,
the actual de jure population in an area and we are also
adjusting that for the measure of the undercount which we estimate
from the Census coverage survey. That takes into account the differential
undercount by age and sex for example.
14. So we are a lot slower than the US and India.
(Mr Cook) The Indian count was actually a head count.
Where I come from in New Zealand the Census results were published
not too much after the Census but they were the first count of
the forms themselves in the areas. The full results come out about
a year after that. When you make those comparisons you need to
compare exactly what you have.
15. I cannot think of any other scientific endeavour
where a population of objects or people is explored by looking
at every single one. I should really like to take you back to
this question of whether we would not be able to get an equally
accurate picture by looking in more detail perhapsso perhaps
one could have more questionsat a population of let us
say 100,000, where you do not feel that even if that were not
done every time it would be an option to replace every second
census for instance.
(Mr Cook) Some countries have had, as we had in the
past, samples of households who are asked large parts of the Census
questions. For example, 10 per cent of the population may be asked
the full form. In other countries, France and Israeland
we are investigating it ourselvesthere is a rolling census
where about 10 per cent of the population are included in a rolling
census every year and we come back to a basic population register.
That allows us once a year to have an updated view of the population.
What is important, what causes the quest for detail, is that when
it comes to the end uses of the Census, a large part of it is
about understanding the age and family structures of often quite
small family groups: it could be an ethnic community which lives
in a particular part of the country and regional groups. In local
government for example there is a huge interest in understanding
the population in quite small areas. If you are planning transportation
policies you actually want to know how people in this or that
pocket use this particular mode of transport. For many of the
uses of the Census in local government it is the very richness
and detail of the Census which makes it valuable.
16. Could you imagine that it would be possible
to delegate aspects of the Census to take account of these local
concerns so that you have a core of questions which will be asked
for a larger population and local authorities could commission
additional questions for their area?
(Mr Cook) That is possible. In some ways you could
say we do that nationally now. As in health, the interests of
a particular sector of public policy nationally tend to place
some weight on whether a particular question should be included
or excluded. If you were to do that regionally it would have an
impact on how you managed the Census regionally. It would have
an impact on how you manage the national publicity campaign. To
answer your question in a slightly different way, the shift in
access to administrative data in the UK is moving us more and
more to a Nordic country type model where we can look at the balance
of what we collect in the Census and what we get from other sources.
That has been very much part of the ONS policy and the question
is: do we have a 2011 Census?
17. What were the main lessons which came out
of the conduct of the 1991 Census?
(Mr Pullinger) We judged the 1991 Census overall to
be successful and we built an awful lot on the successes which
took place that time. One particular example which has already
been mentioned today was the inclusion of an ethnic question for
the first time. It had been very, very contentious during the
period up to that; certainly when we were thinking about the 1981
Census. That came off and it was quite ground breaking and something
we thought was very good and has proved to be very useful. In
the areas where it was less successful, the most critical one
was that the coverage was much poorer amongst some groups than
amongst others. Key to our whole strategyand maybe helping
to answer some of the earlier questionshas been to try
to minimise the amount of differential undercoverage, for example
the fact that young men are much less likely to respond than some
other groups, certain ethnic minority groups are less likely to
respond and other groups may be slightly more surprising. Babies
are difficult to catch; people forget to put them on. Elderly
women too who may be reluctant to open the door. In 1991 we found
quite significant different patterns. For 2001 the critical lessons
we learned were first of all to target our effort to those communities
which were most difficult to get at, especially the inner city
areas where we knew we were going to have problems. So we focused
our resources much more. Secondly, and possibly most critically,
this whole concept of taking account of the people we had missed
in producing the results. That has added to the time to produce
them. In 1991 what was happening was that we produced a first
set of results, area by area, but people found it very difficult
to understand what sense they could make of those results because
it was not until a long time afterwards that we were able to say
that 20 per cent of young men in some inner cities had been missed.
It is very difficult to judge without having made those adjustments.
Central to our strategy this time has been to look at the primary
requirement of people, which is how many people of what characteristics
exist in the population, rather than how many we happen to have
been able to count in the Census.
18. Can you say now that you have overcome those
problems in the 2001 Census?
(Mr Pullinger) I would be foolish to say the Census
was easy: it was very, very hard. The problems we expected to
encounter we did and in some senses with more of a vengeance than
we expected. Finding people in the inner cities, persuading them
to fill in the form, was a huge challenge. It was not just taking
account of issues which happened last time, but changes in society
over the last ten years have really made things more difficult.
More properties with entryphones or security systems, more people
not in the house at any sensible time or any time at all in some
cases, more people living alone. We targeted that. Our enumerator
field force were calling at all times of the day or night, they
were calling back on several occasions. We believe we have been
successful in all the fundamentals, but I am sure there will be
some small pockets where we have struggled in the actual collection.
We are confident that the overall strategy, which allows for those
areas where we will have difficulty, were successful in the end.
19. What were the main changes in 2001 compared
with the conduct of the Census in 1991.
(Mr Pullinger) The main changes of the conduct. Firstly
we planned it much more thoroughly from an earlier time and that
was a key recommendation which came out from the National Audit
Office report. There was a lot of testing of questions, whether
they would be acceptable to people, whether they would be useful;
an awful lot of testing. We had 150,000 in a complete rehearsal
of the Census just to see whether the procedures worked. An awful
lot of upfront work. The second thing which was a big change was
involving local communities, particularly amongst ethnic minorities.
We had a scheme which involved about 3,500 different groups in
the population who could help us get into particular areas; religious
groups especially were very supportive of this as they saw it
as a means of getting their own communities recognised in the
Census. A lot of effort went into that. The adoption of a post-back
methodology for collecting the forms. In the past an enumerator
has gone to the door to deliver the form and then gone back to
collect it. The issues to do with the Post Office have already
been mentioned but this time it was a huge leap forward for us
to be able to save the cost of people going twice, but also for
the vast majority of people who are quite happy to post a form
back for them just to do it and not have to fiddle around with
that afterwards. That was on the collection side. On the processing
side, we have made huge changes in the technology we are using
and in the way we are acquiring the technology, using the opportunities
of engaging the private sector. The Lockheed Martin contract has
been pivotal to that. If you went to our processing site in Widnes,
it really is state-of-the-art technology which is out-of-sight
different to what we had before. Two more things then I will stop.
The first thing is the coverage survey adjusting for the results.
The final one will be producing the results using the Internet
which we would not have done last time.