Background
The Government Actuary’s Department became responsible
for the production of the official UK national projections
in 1954. Projections were produced every year from a 1954-based
set until the 1979-based set. They were then produced every
second year until the 1991-based set. There was then a
1992-based set, since when ‘full’ projections
have again been produced every second year until the 2004-based
set. In the intervening year between full projections, ‘interim’ sets
of national projections may be produced. An interim set
of 2001-based projections was produced shortly after the
publication of the first results from the 2001 Census and
an interim set of 2003-based projections was published
in 2004 following significant revisions to the starting
population on which they were based.
All national projections since the 1998-based set were
made available online on the GAD website at the time of
their publication. In January 2006, the database of past
national projections was extended back to the 1971-based
set. In October 2006, the database was further extended
in limited format back to the 1954-based set of projections.
Content of database
The database provides detailed information on most national
population projections produced since the introduction
of the Office for National Statistics (formerly, the Office
for Population Censuses and Surveys) PP2 Series of reference
volumes. This series began with the volume for the 1970-based
projections which was published in 1971.
The database includes the projections made at two yearly
intervals from the 1971-based set to the 1991-based set,
followed by the 1992-based and all subsequent sets. Apart
from the 1971-based set (see below), this section of the
database contains projections for both the United Kingdom
as a whole and for the four constituent countries. For
the 1998-based set onwards, projections at Great Britain
and England & Wales (combined) level are also included.
For the 2000-based set onwards, variant projections are
provided as well as the principal (central) projections.
For all projections from the 1971-based set to the 1998-based
set, the database gives projected populations by five year
age group as well as components of change and summary indicators
such as total fertility rates and (period) life expectancy.
These older projections are presented in the same format
as has been used for more recent projections, which were
made available online at the time of their publication.
In addition, the 2000-based and later sets also include
more detailed results which are not available for earlier
projections.
Some very limited information from the projections made
prior to the start of the PP2 Series of reference volumes
has also been uncovered. The database has therefore been
extended to include the available information from the
first (1954-based) official projection made by GAD and
every second projection from the 1955-based set to the
1969-based set.
Sources of information
The historic database has been created from a variety
of sources. Electronic records were available back to the
1987-based projections. For the 1979-based to 1985-based
projections, the detailed results were available on microfiche.
Prior to the 1979-based projections, the sources were the
PP2 reference volumes, some surviving paper records held
by GAD and the former annual publication the Registrar
General’s Statistical Review of England & Wales.
The presentation of the national projections results has,
of course, developed throughout the period since GAD took
over responsibility for projections in 1954. As far as
possible, we have tried to recreate the past projections
in the same format as they are presented today. However,
especially for the earliest projections, this presented
some difficulties. The main points to note are:
Populations of working age and pensionable
age and associated dependency ratios
These figures are available from the ‘Components of
change and summary indicators’ tables.
The Pensions Act 1995 announced a change in state pension
age from 65 for men and 60 for women as at present, to
65 for both sexes. This change is to be phased in between
2010 and 2020. For all projections from the 1996-based
set onwards, the projected working age and pensionable
age populations (and the dependency ratios calculated from
them) allow for this change (click here for further details.
However, for all projections up to and including the 1994-based
set, the future working age and pensionable age populations
were calculated using a constant state pension age of 65
for males and 60 for females.
So, from 2010 onwards, the projected working age and pensionable
ages populations, and the dependency ratios derived from
them, are not directly comparable for the projections made
before and since the 1996-based set.
Mean and median age
These figures are available from the ‘Components
of change and summary indicators’ tables.
Mean and median age figures were not published prior to
the 1996-based projections. They have now been calculated
for earlier projections. However, it was not possible to
calculate mean age for projections before the 1987-based
set.
Expectations of life and total fertility rates
These figures are available from the ‘Components
of change and summary indicators’ tables.
The summary indicators of (period) expectation of life
at birth and total fertility rate were not routinely published
in the oldest projections. Figures for expectation of life
at ages 50, 65 and 80 were first published for the 1996-based
projections. It has been possible to derive all of the
missing figures from the available information on fertility
and mortality rates. However, prior to the 1987-based projections
(for mortality) and the 1983-based projections (for fertility),
we do not have complete information on the assumed fertility
or mortality rates and the summary indicators have been
calculated using approximate methods. We are confident
that any errors in recreating these indicators in the older
projections will be very minor.
1973-based projections
For this set of projections only, age distributions and
statistics derived from them (e.g. median age and dependency
ratios) were only available for each year up to 1986 and
then for every fifth year up to 2011, and also 2013. However,
annual population totals and full components of population
change data are provided.
1971-based projections
In the 1971-based projections, separate projections were
not published for England and Wales individually. Therefore,
for this set of projections only, the database includes
results for England & Wales (combined) as well as for
Scotland and Northern Ireland and the United Kingdom as
a whole.
1954-based to 1969-based projections
Only United Kingdom and England & Wales (combined)
results are available for these projections, except for
1954-based where only UK data is available. Projected populations
by five-year age group are given on the database but the ‘Components
of change and summary indicators’ tables are not
available for these projections.
The United Kingdom and England & Wales (combined)
data were derived from separate sources. In some instances,
these sources gave data for different years. For example,
for the 1965-based set, the UK projection is available
for the year 2000 but not 2001, while the England & Wales
projection is available for 2001 but not 2000. All the
available data have been included on the database and a
blank column for a particular year in the United Kingdom
table indicates that data for that year are available in
the corresponding England & Wales table and vice versa.
Accuracy of data
Source data has been used in the most accurate form available
but in some instances this was in a rounded format. These
rounded figures necessarily had to be used to calculate
some of the missing derived statistics. In the spreadsheet
tables, population numbers are displayed rounded to the
nearest thousand, while some derived statistics are displayed
rounded to one or two decimal places. We are confident
that there are no significant errors in the data at the
level at which they are displayed. However, for ease of
production of the tables and for the convenience of users,
figures are often stored in the spreadsheets to more decimal
places than they are displayed. In some cases, they will
not be accurate to this extra level of precision.
Article on the accuracy of past projections
An article was published in the summer 2007 edition of
Population Trends
(no. 128) which considers the accuracy of the national population
projections over the last fifty years. The full article can be found here
Further information
For any enquiries about the historical projections database,
please contact natpopproj@ons.gsi.gov.uk
