2002-based national population projections for the United Kingdom and constituent countries

The 2002-based national population projections, carried out by the Government Actuary in consultation with the Registrars General, show the population of the United Kingdom rising from 59.2 million in 2002 to nearly 65 million by 2031. Longer-term projections suggest the population will peak around 2050 at over 65 million and then gradually start to fall. The population will become gradually older with the median age expected to rise from 38.2 years in 2002 to 43.3 years by 2031. In 2002, there were around 850 thousand (8 per cent) more children aged under 16, than people of state pensionable age. However, from 2007, the population of pensionable age is projected to exceed the number of children.     

2004-based national population projections for the UK and constituent countries

The 2004-based national population projections, carried out by the Government Actuary in consultation with the Registrars General, show the population of the United Kingdom (UK) rising from 59.8 million in 2004, passing 60 million in 2005 and 65 million in 2023, to reach 67.0 million by 2031. In the longer-term, the projections suggest that the population will continue rising beyond 2031 but at a much lower rate of growth. The population will become older with the median age expected to rise from 38.6 years in 2004 to 42.9 years by 2031. With the current plans for a common state pension age of 65 for both sexes from 2020, the number of people of working age for every person of state pensionable age is projected to fall from 3.33 in 2004 to 2.62 by 2031.     

1998-based national population projections for the United Kingdom and constituent countries

The 1998-based national population projections, carried out by the Government Actuary in consultation with the Registrars General, show the population of the United Kingdom rising from 59.2 million in 1998 to over 63.5 million by 2021. Longer-term projections suggest the population will peak around 2036 and then gradually start to fall. The population will become gradually older with the median age expected to rise from 36.9 years in 1998 to nearly 42 years by 2021. In 1998, there were 1.4 million (13 per cent) more children aged under 16, than people of pensionable age. However, by 2008, the population of pensionable age is projected to exceed the number of children.     

2006-based national population projections for the U.K. and constituent countries

The 2006-based national population projections, carried out by the Office for National Statistics in consultation with the devolved administrations, show the population of the UK rising from 60.6 million in 2006, passing 65 million in 2016 and 70 million in 2028, to reach 71.1 million by 2031. In the longer-term, the projections suggest that the population will continue rising beyond 2031 for the full length of the projection period. The population will become older with the median age expected to rise from 39.0 years in 2006 to 41.8 years by 2031. Since the last projection round legislation has been passed to increase the state pension age from 65 to 66 for both sexes between 2024 and 2026. Despite this change, the number of people of working age for every person of state pensionable age will reduce from 3.32 in 2006 to 2.91 by 2031. The legislation includes further increases in the state pension age to 68 for both sexes by 2046.     

2000-based national population projections for the United Kingdom and its constituent countries

The 2000-based national population projections, carried out by the Government Actuary at the request of the Registrars General, show the population of the United Kingdom rising from 59.8 million in 2000 to nearly 65 million by 2025. Longer-term projections suggest the population will peak at nearly 66 million around 2040 and then gradually start to fall. The population will become gradually older with the median age expected to rise from 37.4 years in 2000 to 42.4 years by 2025. In 2000, there were 1.3 million (12 per cent) more children aged under 16, than people of state pensionable age. However, by 2007, the population of state pensionable age is projected to exceed the number of children.     

Interim 2001-based national population projections for the United Kingdom and constituent countries

This article describes new 2001-based national population projections which were carried out following the publication in September 2002 of the first results of the 2001 Census. These "interim" projections, carried out by the Government Actuary in consultation with the Registrars General, take preliminary account of the results of the Census which showed that the base population used in previous projections was overestimated. The interim projections also incorporate a reduced assumption of net international migration to the United Kingdom, informed by the first results of the 2001 Census and taking account of more recent migration information. The population of the United Kingdom is now projected to increase from an estimated 58.8 million in 2001 to reach 63.2 million by 2026. The projected population at 2026 is about 1.8 million (2.8 per cent) lower than in the previous (2000-based) projections.     

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.     

Fertility assumptions for the 2006-based national population projections

Fertility is one of the key components of the national population projections, alongside mortality and migration. For the 2006-based population projections, long-term completed family size in the U.K. is assumed to be 1.84 children per woman. This represents an increase of 0.10 on the assumption of 1.74 children per woman used in the 2004-based round. Although the U.K's long-term fertilit assumption has been lowered several time in recent years, this is the first time it has been raised since the 1960s baby boom. This article outlines why ONS decided to raise the long-term fertility assumptio for all four U.K. countries in the 2006-based population projections     

Assumptions for the 2000-based national population projections

This article summarises the long-term assumptions of fertility, mortality and net migration which will underlie the forthcoming 2000-based national population projections. Compared with the current (1998-based) projections, the new projections will assume lower levels of fertility, but higher levels of inward net migration. There will be relatively little change to mortality assumptions. Results of the new projections will be available on 15 November 2001.     

Population of households in England to 2021

This article outlines the methodology and results of the Department of the Environment, Transport and the Regions (DETR) 1996-based household projections for England, and its regions. It examines differences between this round of projections and the previous 1992-based round. The 1996-based projections indicate that between 1996 and 2021 a growth of 3.8 million households can be expected in England, if recent trends continue. Both the national and subnational methodology and results are covered.     

基于合理膳食结构的2020-2050年我国食物用粮需求测算

测算我国未来粮食需求量是制定我国粮食安全相关政策措施的基础.目前我国城镇化水平加快,老龄化问题突出,完全二孩生育政策刚刚实施,正处于人口结构转型的关键期,而人口结构变动直接影响食物用粮需求.本文从满足居民营养健康标准的食物需求视角下,考虑人口年龄、性别和城乡结构,采用标准人消费系数法,测算了单独二孩政策、完全二孩政策和完全放开生育政策情景下2020-2050年我国食物用粮（包括口粮与饲料粮）的需求,并进行对比分析.结果表明：在完全二孩政策情景下,我国食物用粮需求将在2030年达到峰值39263.1万吨,比通常采用人均方法的计算结果低10061.0万吨;因城镇化率的提高将使2020、2030与2050年食物用粮需求分别增加约406.7万吨、1142.5万吨与1553.8万吨;生育政策调整所带来的人口规模与结构变化并不是2020-2050年我国粮食安全的主要影响因素.建议积极引导和鼓励生育,在适当时间进一步完全放开生育;同时采取有效措施将粮食损耗与浪费降到最低.     

Looking back to look forward: lessons from four birth cohorts for ageing in the 21st century

Government projections indicate that by 2026 the number persons aged 60 and over living in Britain will reach 17.1 million, giving rise to concerns about the social and economic costs of an ageing population. Little attention, however, has been paid to the likely socio-economic characteristics of those retiring in the twenty-first century, and how they may differ from previous cohorts of elderly persons. This research analyses data from the General Household Survey (1974-1996) to examine the social and economic experiences of four birth cohorts. Findings indicate significant differences in the living arrangements, health and access to resources amongst the cohorts, which will have implications for the retirement prospects of the post-war baby boom generations in 2020 and beyond.     

Family building intentions in England and Wales: trends,outcomes and interpretations

This article presents and analyses women's childbearing intentions collected in the General Household Survey (GHS). Data from the 21 surveys from 1979 to 2001 show that over that period there has been a fall in women's intended numbers of births. However the latest data (from the 1998, 2000 and 2001 surveys) show that the average number of children intended is still around two, somewhat higher than the average number of children current fertility rates suggest women will have. The questions of whether this difference can be interpreted as possible unmet need for children, whether past intentions have been good predictors of fertility, and how current intentions may be used to inform projections assumptions are discussed. In relation to the last question, fertility intentions by ethnic group are also presented.     

Fifty years of United Kingdom national population projections: how accurate have they been?

This article considers the accuracy of the official national population projections made for the UK over the last fifty years The findings take account of the revision to population estimates following the 2001 Census and are largely similar to the findings of a previous review carried out after the 1991 Census. The total population has been projected reasonably accurately but this is largely a chance result of compensating errors in the assumptions of fertility, mortality and net migration. The largest differences between projected and actual populations are for the very young and the very old, while projections of the working age population have been comparatively accurate. Fertility and mortality errors have reduced in more recent projections, while migration errors have grown. However, this may simply reflect the volatility or stability of the respective time-series at the time the projections are made. Changes in estimates of the past and current size of the population (highlighted by the revisions made to population estimates following the 2001 Census) are also shown to play a part in explaining projection error.     

Variant population projections for the United Kingdom and its constituent countries

Interest has been growing steadily in understanding the impact of the inherent uncertainty in the national population projections. As a result, the Government Acturay's Department has recently produced the most extensive set of official variant projections ever published in the United Kingdom. These include 'standard' variants based on alternative high and low assumptions for future fertility, life expectancy and net migration and also a number of 'special case scenarios.' All of these variants have been produced at both UK and individual country level. This article describes the full range of variant projections available from the 2000-based national projections and summaries some of the key results for both the UK and the individual countries.     

微观创新驱动下的中国能源消费与碳排放趋势研究

以基于自主体模拟和投入产出模型为建模手段,在宏观层面构建了中国17个部门的投入产出模型,在微观层面构建了部门细分的企业创新模型。模型通过微观企业自主体的创新驱动宏观层面部门间投入产出关系、能源消费量和碳排放趋势的演化。研究发现,由于技术创新的不确定性,使得能源消费峰值和碳排放峰值出现的年份存在不确定性。能源消费峰值年份在2025年至2036年期间呈现正态分布;而碳排放峰值年份在2024年至2033年间呈现正态分布;其中,能源消费峰值出现的概率最大年为2031年,概率为23.57%;碳排放峰值出现的概率最大年为2029年,概率为33.51%。以多次模拟的平均值分析,中国未来能源消费量的高峰约出现在2031年,高峰值为5146Mtce;中国碳排放高峰出现在2029年,峰值为2.7GtC。     

Immigration, emigration and the ageing of the overseas-born population in the United Kingdom

This article uses data from the 1971 and 2001 Censuses, the 1999-2003 Labour Force Survey and the 1977 to 2002 International Passenger Survey to investigate the migration processes contributing to the age structure and ageing of the UK's overseas-born population. Overall almost half of recent decades' immigrants to the UK emigrate again within five years of arrival, but with large variation by overseas country of birth. Between half and two thirds of the immigrants born in the continental European Union, North America and Oceania emigrate again within five years, while 15 per cent of those born in the Indian subcontinent do so. Significant cumulative emigration more than five years after arrival is seen among earlier immigrants from the Indian subcontinent, the Caribbean Commonwealth and Europe. Large country-of-origin variations in the ratio of pension-age population to working-age population primarily reflect the country composition of immigration streams 30 or more years before.     

Modelling student age-groups in the subnational population projections for England: an investigation into potential improvements

This article describes research aimed at improving modeling of student age-groups in the ONS subnational population projections for England. A number of data-sources were investigated, and the research focused on Higher Education Statistics Agency data. Although the coverage of HESA data is not sufficient to enable student populations to be projected separately, the data have been used to devise an adjustment method for the student-age population. Both the data and method will be monitored and, if appropriate, used in future projections.     

The 2011 Census: a proposed design for England and Wales

This article sets out the proposed design for a 2011 Census in England and Wales, as part of the ONS's proposed future population statistics system. The design draws on experiences from the 2001 Census and changes in available technology, and takes account of the many comments received from respondents to a Discussion Paper published in October 2003 and of views expressed at a joint ONS/RSS Conference on 11-12 November 2003. The article highlights the statistical and operational strategic aims for the 2011 Census, the major changes proposed from the 2001 approach, and gives an indication of the benefits and risks. It is important to note that this design remains a proposal at present, the elements of which will be subject to further research building on comments received during consultation and a detailed testing programme over the coming years.     

A comparison of official population projections with Bayesian time series forecasts for England and Wales

We compare official population projections with Bayesian time series forecasts for England and Wales. The Bayesian approach allows the integration of uncertainty in the data, models and model parameters in a coherent and consistent manner. Bayesian methodology for time-series forecasting is introduced, including autoregressive (AR) and stochastic volatility (SV) models. These models are then fitted to a historical time series of data from 1841 to 2007 and used to predict future population totals to 2033. These results are compared to the most recent projections produced by the Office for National Statistics. Sensitivity analyses are then performed to test the effect of changes in the prior uncertainty for a single parameter. Finally, in-sample forecasts are compared with actual population and previous official projections. The article ends with some conclusions and recommendations for future work.