New estimates of trends in births by birth order in England and Wales

A greater understanding of past, present and future trends in fertility can be gained from analysing trends in birth order; that is whether a birth is a first, second, third or higher order birth. However, under current legislation, birth order information is not collected at registration for births outside marriage and birth order recorded within marriage is not the true birth order. This article presents revised and updated estimates of true birth order. It discusses the construction of the new estimates and presents analysis relating the births by true birth order to the population of women by parity on both a period (fertility in a particular year) and cohort (fertility of women born in a particular year) basis. The new true birth order figures are also compared to the previous set of estimates.     

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.     

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.     

Geography for the 2001 Census in England and Wales

This article provides an overview of 2001 Census geography systems in England and Wales, concentrating primarily on the creation of output geography. It is important to note that there are significant differences between the systems being implemented in England and Wales and those which apply to Northern Ireland and Scotland. The Northern Ireland system is broadly similar to that described here, whereas the entire data infrastructure and output area design process in Scotland are different.     

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.     

Small area population estimates project: data quality of administrative datasets

The Office for National Statistics (ONS) has set up a project to investigate the feasibility of producing postcensal small area population estimates on a nationally consistent basis for England and Wales. Research has taken place to identify datasets that could potentially be used within a method to produce small area population estimates. Following an evaluation of a number of different administrative datasets, the most suitable have been short-listed for further consideration. This article presents the findings of the evaluation, based on 2001 data, and summarises the characteristics of these short-listed data sources. This article does not cover the methods that are being evaluated as part of the feasibility assessment.     

Replacement fertility, what has it been and what does it mean?

Replacement fertility is a term commonly used by demographers when referring to levels of childbearing and yet is rarely explained. It is normally presented as being around 2.1 children per woman. Continued below replacement fertility in developed countries and fertility falling in developing countries has given the concept of replacement fertility a higher profile. This article explains how replacement level is calculated and explores the concept further. Past replacement fertility levels are calculated for England and Wales. A possible alternative definition of replacement is also presented. Simple projection scenarios are used to show the effect on population of below replacement fertility, and also of postponement of fertility. The importance and implications of below replacement fertility are discussed.     

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.     

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.     

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.     

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 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.     

Have national trends in fertility between 1986 and 2006 occurred evenly across England and Wales?

During the past 20 years fertility patterns within England and Wales have changed considerably. The total fertility rate experienced a prolonged decline during the 1990s and hit a record low in 2001. Since then the level of fertility has increased fairly rapidly. Over the two decades, fertility has been constantly increasing at ages above 30, and as a consequence the mean age of motherhood has been rising. This article explores fertility trends within statistical regions and local authorities to improve our understanding of changes in fertility at the subnational level between 1986 and 2006.     

Home births in the UK, 1955 to 2006

This article presents data on trends in the percentage of maternities taking place at home in the UK. As well as the national trend, the article examines how home maternity levels vary according to mother's age, number of previous live births within marriage, country of birth, region, local authority and NHS Trust. Examination of trends and variations in home maternity levels provides a context for debates regarding factors that may influence where women give birth.     

The use of patient registers to estimate migration

This article presents information discussed at the recent regional seminars on population statistics. It describes a new data source for estimating internal migration between local and health authorities in England and Wales, discusses the way that the data have been collected and processed, and how limitations in the raw data have been addressed. It then goes on to explain the way that the new internal migration estimates have been used in the calculation of population estimates for local and health authorities. This is a change to the method of estimating migration in the calculation of population estimates.     

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.     

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.     

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.     

Methodology used for producing ONS's small area population estimates

The Office for National Statistics (ONS) has set up a project to investigate the feasibility of producing postcensal small area population estimates on a nationally consistent basis for England and Wales. Following on from earlier investigations to identify potential data sources and methods, ward and Super Output Area population estimates have been released as 'experimental statistics'. This article covers the methodology used to produce these estimates, feedback from user consultation with the initial estimates released at ward level, summary statistics on the population estimates for mid-2001 to mid-2003, and future developments for small area population estimates.     

The long shadow of childhood: associations between parental social class and own social class, educational attainment and timing of first birth; results from the ONS Longitudinal Study

In September 2004, linked data from the 2001 Census was made available in the Office for National Statistics (ONS) Longitudinal Study (a 1 per cent sample of the population of England and Wales). The study now includes information from four censuses on sample members and the people they lived with. The availability of this new information, the length of follow-up and other features of the study (such as records of births and deaths to sample members) provide new opportunities for analysing change--both over the life course, between time periods, and between generations. This article illustrates the potential for analysis of continuity and change with new results on intergenerational social mobility, and on parental social class and age at first birth.