Looking beyond the 2001 Census

This article outlines the Office for National Statistics' strategic review process for the best way of meeting users' future requirements for information that has traditionally been collected by taking a census. It reports on a possible design for such a census in 2011 but also considers alternative approaches to collecting comparable information. The work described in this article is being undertaken within ONS and relates essentially to research on the census in England and Wales only. The General Register Office for Scotland and the Northern Ireland Statistics and Research Agency are, however, carrying out similar reviews.     

Population bases and the 2011 Census

In an increasingly complex society there are a number of different population definitions that can be relevant for users, beyond the standard definition used in counting the population. This article describes the enumeration base for the 2011 Census and how alternative population outputs may be produced. It provides a background as to how the questions on the questionnaire were decided upon and how population bases can be constructed from the Census. Similarities and differences between the information collected across the three UK Censuses (England and Wales, Scotland and Northern Ireland) are discussed. Finally, issues around estimating the population on alternative bases are presented.     

Fertility assumptions for the 2002-based national population projections

One of the key components of national population projections is the assumed level of fertility, which determines the number of future births in the projections. Assumptions are made in terms of the average number of children women will have over their lifetime. For the 2002-based projections this average is assumed to ultimately be 1.75 for England and for Wales, 1.60 for Scotland, and 1.80 for Northern Ireland, leading to a United Kingdom assumption of 1.74. This article explains how these overall assumptions, which are the same as assumed in the 2000-based and interim 2001-based projections, are derived. It also explains why these levels are higher than current 'period' indicators of fertility. Finally, information on more detailed age specific fertility rates, and implications for family size distributions, is given.     

Estimates of true birth order for Scotland, 1945-1999

Over the last three decades fertility in Scotland, as measured by the total fertility rate (TFR), has moved from being higher than in England and Wales, to being lower. The annual number of births in Scotland has declined so that in the mid-1990s low fertility became the main driver of the overall population decline that Scotland has been experiencing since 1974. Analysis of fertility by birth order is instrumental in gaining an understanding of past and future fertility trends. Until the rise in births outside marriage in the 1980s data from registration could be used as a proxy for true birth order. However, because birth order is not collected for births outside marriage true birth order now has to be estimated. This article presents the first official estimates of true birth order for Scotland. The construction of these estimates based on a modified version of the method used for England and Wales is discussed. This article also presents analysis relating births by true birth order estimate to the population of women by parity on a cohort basis, and makes comparisons with England and Wales.     

Geographic variations in conceptions to women aged under 18 in Great Britain during the 1990s

This article examines geographic variations in conceptions to women aged under 18. It presents data on conception rates and the percentage leading to abortion for the three countries of Great Britain, the Government Office Regions of England and local authorities within Great Britain. It provides an overview of variations between areas at each of the three geographic levels and examines whether this variation is associated with the social and demographic characteristics of local authority areas. This article is the first occasion on which conception rates for Scotland have been published on a comparable basis to England and Wales and also the first use of the revised ONS classification to examine conceptions to women aged under 18.     

The Millennium Cohort Study

The Millennium Cohort Study is the latest in the line of British birth cohort studies. MCS resembles its predecessors which follow people born in 1946, 1958 and 1970 in the intention to become multi-purpose longitudinal data resource charting many aspects of individual's lives over time. The families of a sample of around 20,000 babies are being interviewed during 2001-02, when eligible babies reach 9 months, to establish the conditions from which they set out in life. The survey contrasts with the previous cohort studies in various ways. Instead of taking all births in one week, the sample of births is spread over a year; the births are from a selection of electoral wards, thereby enabling eventual analysis by neighbourhood characteristics; it also over samples children living in deprived areas, wards with high ethnic minority populations and samples have been boosted in Scotland, Wales and Northern Ireland. The latter UK country has not been covered by the other studies. It interviews fathers as well as mothers, and given that its initial funding comes via the ESRC, puts a greater emphasis on socio-economic data than in early parts of the other studies. MCS has been enhanced by additional Government funding. The research team, based at the Institute of Education, aims to deposit a multi-purpose dataset for public use at the ESRC data Archive in the Spring of 2003.     

Short-term international migration trends in England and Wales from 2004 to 2009

Short-term migration estimates for England and Wales are the latest addition to the Office for National Statistics (ONS) migration statistics. This article discusses definitions of short-term migration and the methodology that is used to produce the estimates. Some of the estimates and the changes in the estimates over time are then discussed. The article includes previously unpublished short-term migration statistics and therefore helps to give a more complete picture of the size and characteristics of short-term international migration for England and Wales than has previously been possible. ONS have identified a clear user requirement for short-term migration estimates at local authority (LA) level. Consequently, attention is also paid to the progress that has been made and future work that is planned to distribute England and Wales short-term migration estimates to LA level.     

An international comparative study on the use of the Cohort Component Method for estimating national populations

This comparative study explores the use of the Cohort Component Method (CCM) to produce national level population estimates. This method is used annually to calculate mid-year population estimates for England and Wales by the Office for National Statistics (ONS). Initially the article considers recent population change in England and Wales, with particular emphasis on the growing importance and challenges faced by migration estimation. Comparisons are then made between how population estimates are produced in England and Wales and other countries, with a particular focus on differences in the way the CCM is applied. Recent changes in methods used to estimate population are then reviewed along with a discussion of alternative approaches such as those described in academic literature.     

Estimating fertility rates using the ONS Longitudinal Study--what difference does the inclusion of non-continually resident members make?

Among datasets available for fertility research in England and Wales, the Office for National Statistics (ONS) Longitudinal Study (LS) is unique in its construction and scale. The large number of individuals who are part of the study means that it is an important dataset for estimating fertility trends in England and Wales by age and parity. This article uses the LS to estimate age-specific fertility rates (ASFRs) for England and Wales between 1991 and 2001. This necessitates great care to ensure that the exposure to risk of birth for female LS members is fully understood. To achieve this, two forms of residential history are defined - consistent cases where the residential information for the LS member is potentially complete for the whole decade and inconsistent cases where there is certainly some form of incompleteness in the residence information. By considering 'all consistent cases', that is both the continuously resident plus those who are not continuously resident but appear to have a complete residential history, we obtain ASFRs which are slightly lower than official statistics figures, but closer to these official figures than ASFRs produced when restricting the sample to LS members who remain continuously resident between 1991 and 2001. The fertility of those consistent cases who are not continuously resident is substantially higher than the rates of continuously resident cases.     

A demographic statistics service for the 21st century

This article provides a summary of a review of the uses made of population and household statistics across government in England and Wales, setting out the policy and statistical impacts of demographic change. It looks at the broad span of government uses of population and household statistics--and what these uses imply for the qualities inherent in these statistics. The article considers alternative population definitions and refers to several ongoing projects that are aiming to enhance demographic statistics in England and Wales. Following an analysis of the key issues relating to the implementation of an improved statistical service, a series of action points for ONS emerging from the review is set out.     

How important are intergenerational cycles of teenage motherhood in England and Wales? A comparison with France

Teenage fertility has fallen substantially in every Western European country except the United Kingdom. This article examines the hypothesis that repetition of teenage motherhood from mother to daughter is a major cause of the UK being the exception. A simple demographic model of fertility across generations is estimated with comparable data from England and Wales and France. The main finding is that mother-daughter repetition can account for only a minor part of the total difference in teenage childbearing between the two countries, especially over the long term. The higher teenage childbearing in England and Wales of those whose mothers began childbearing after their teenage years dominates.     

The effect of changes in timing of childbearing on measuring fertility in England and Wales

Changes in the ages at which women give birth to their children mean that fertility measured at a particular point in time (period) may not be a good representation of the ultimate fertility of those women. The common measure of period fertility is the total fertility rate, which in 2001 has fallen to the lowest level since records began in England and Wales. This article presents various methods that have been proposed to adjust period fertility data to take account of changes in the timing of childbearing, applied to England and Wales data. The article concludes that while these adjustment methods provide useful insights, for example, that the total fertility rate has underestimated period quantum fertility since the 1970s, the measures produced are difficult to interpret. This is in part because the concept they are trying to measure, period quantum is itself imprecise. The adjustments do not necessarily provide a reliable indicator of underlying cohort fertility.     

Reviewing the mid-year population estimates in Northern Ireland

This article describes the thorough review of the mid-year population estimates for Northern Ireland. No major problems have been identified with the current estimates but a number of enhancements have been put in place. The new figures are consistent with a number of administrative data sources. The overall effect has been to revise the estimated Northern Ireland population by about 6,000 people, or between 0.3 and 0.4 per cent, for each year between 1991 and 1997. The revised estimates for Northern Ireland have been incorporated into the population figures for the United Kingdom included in the Table section of this issue of Population Trends.     

Estimating the changing population of the 'oldest old'

The population of England and Wales is becoming older. This poses an increasing demand for detailed data on the size an trends of the population at the oldes ages. Using the recently released Offic for National Statistics estimates of th population aged 90 and over in England and Wales, this article shows trends in the population of the oldest old and demographic causes of the rapid increase in centenarians during the twentieth century. It also presents further validation of the ON estimates of the oldest old with estimat from other data sources.     

Population review of 2004 and 2005: England and Wales

This article outlines the main features of the population of England and Wales in 2005. Where 2005 figures have not yet been published, data for 2004 are given.     

Population review of 1998: England and Wales

This article outlines the main features of the population of England and Wales in 1998. Where 1998 figures have not yet been produced, data for the latest available year are given.     

Population review of 1999: England and Wales

This article outlines the main features of the population of England and Wales in 1999. Where 1999 figures have not yet been produced, data for the latest available year are given.     

Population review of England and Wales, 2001

This article describes the main features of the population of England and Wales in 2001. Where 2001 figures have not yet been produced, data for the latest available year are given.     

The changing demographic picture of the UK: national statistician's annual article on the population

The population of the UK is currently growing at its fastest rate since the 1960s, increasing by two and a half per cent between mid-2001 and mid-2006. While life expectancy continues to increase, fertility rates have also been increasing in the last five years and are currently at their highest level since 1980. In addition, international migration has led to the UK population growing by an average of 500 people per day over the last five years. The population is also becoming increasingly diverse and mobile, and these factors make it increasingly challenging to measure population change accurately. This is the first of a series of annual reports on the population of the UK; these reports will provide an overview of the latest statistics on the population and will also focus on one specific topic - for this report the topic is fertility and, in particular, the impact of migration on fertility, but different topics will be covered in future years. The reports will also highlight the key strands of work being taken forward within the National Statistics Centre for Demography in order to improve UK population statistics. More detailed information on the populations of Wales, Scotland and Northern Ireland are available in the annual demographic reports produced by the respective devolved administrations.'     

Improving ONS spatial referencing--the impact on 2000 births and deaths data

This article describes the improvements in the way that ONS will be allocating births and deaths data to administrative and health areas in England and Wales, beginning with data for 2001. Births and deaths registered in 2000 are used to examine the differences in area allocations at ward, local authority and health authority levels, which this change will introduce. Differences in the geographical characteristics of births and deaths are also described.