Labour Force Survey Two-Quarter Longitudinal Dataset, July - December, 2012

<div>Latest Edition Information</div><div>For the fifth edition (July 2019) a new version of the data file, weighted to 2018 population figures, was deposited. </div> <b>Background</b><br> The <i>Labour Force Survey</i> (LFS) is a unique source of information using international definitions of employment and unemployment and economic inactivity, together with a wide range of related topics such as occupation, training, hours of work and personal characteristics of household members aged 16 years and over. It is used to inform social, economic and employment policy. The LFS was first conducted biennially from 1973-1983. Between 1984 and 1991 the survey was carried out annually and consisted of a quarterly survey conducted throughout the year and a 'boost' survey in the spring quarter (data were then collected seasonally). From 1992 quarterly data were made available, with a quarterly sample size approximately equivalent to that of the previous annual data. The survey then became known as the <i>Quarterly Labour Force Survey</i> (QLFS). From December 1994, data gathering for Northern Ireland moved to a full quarterly cycle to match the rest of the country, so the QLFS then covered the whole of the UK (though some additional annual Northern Ireland LFS datasets are also held at the UK Data Archive). Further information on the background to the QLFS may be found in the documentation.<br> <br> <b>Longitudinal data</b><br> The LFS retains each sample household for five consecutive quarters, with a fifth of the sample replaced each quarter. The main survey was designed to produce cross-sectional data, but the data on each individual have now been linked together to provide longitudinal information. The longitudinal data comprise two types of linked datasets, created using the weighting method to adjust for non-response bias. The two-quarter datasets link data from two consecutive waves, while the five-quarter datasets link across a whole year (for example January 2010 to March 2011 inclusive) and contain data from all five waves. A full series of longitudinal data has been produced, going back to winter 1992. Linking together records to create a longitudinal dimension can, for example, provide information on gross flows over time between different labour force categories (employed, unemployed and economically inactive). This will provide detail about people who have moved between the categories. Also, longitudinal information is useful in monitoring the effects of government policies and can be used to follow the subsequent activities and circumstances of people affected by specific policy initiatives, and to compare them with other groups in the population. There are however methodological problems which could distort the data resulting from this longitudinal linking. The ONS continues to research these issues and advises that the presentation of results should be carefully considered, and warnings should be included with outputs where necessary.<br> <br> <b>LFS Documentation</b><br> The documentation available from the Archive to accompany LFS datasets largely consists of the latest version of each user guide volume alongside the appropriate questionnaire for the year concerned. However, volumes are updated periodically by ONS, so users are advised to check the latest documents on the ONS <a href="https://www.ons.gov.uk/employmentandlabourmarket/peopleinwork/employmentandemployeetypes/methodologies/labourforcesurveyuserguidance" title="Labour Force Survey - User Guidance">Labour Force Survey - User Guidance</a> pages before commencing analysis. <b>This is especially important for users of older QLFS studies, where information and guidance in the user guide documents may have changed over time.</b><br> <br> <b> Additional data derived from the QLFS</b><br> The Archive also holds further QLFS series: End User Licence (EUL) quarterly data; Secure Access datasets; household datasets; quarterly, annual and ad hoc module datasets compiled for Eurostat; and some additional annual Northern Ireland datasets. <br> <br> <b>Variables DISEA and LNGLST</b><br> Dataset A08 (Labour market status of disabled people) which ONS suspended due to an apparent discontinuity between April to June 2017 and July to September 2017 is now available. As a result of this apparent discontinuity and the inconclusive investigations at this stage, comparisons should be made with caution between April to June 2017 and subsequent time periods. However users should note that the estimates are not seasonally adjusted, so some of the change between quarters could be due to seasonality. Further recommendations on historical comparisons of the estimates will be given in November 2018 when ONS are due to publish estimates for July to September 2018. <br> <br> An article explaining the quality assurance investigations that have been conducted so far is available on the <a href="https://www.ons.gov.uk/employmentandlabourmarket/peopleinwork/employmentandemployeetypes/methodologies/analysisofthediscontinuityinthelabourforcesurveydisabilitydataapriltojune2017tojulytoseptember2017" target="_blank">ONS Methodology</a> webpage. For any queries about Dataset A08 please email [e-mail].<br> <br>

最新版本信息
2019年7月发布的第五版中，已存档了加权至2018年人口统计数据的新版数据文件。

背景
劳动力调查（Labour Force Survey, LFS）是采用国际统一标准的就业、失业与经济不活跃状态定义，同时涵盖职业、培训、工作时长、16岁及以上家庭成员个人特征等多类相关主题的独特信息来源，其数据被用于为社会、经济与就业政策制定提供参考。该调查自1973年至1983年首次以两年一度的频率开展，1984年至1991年转为年度调查，包含全年开展的季度调查与春季季度的「补充」调查（此后数据按季度采集）。1992年起，季度数据正式对外发布，季度样本量大致与此前年度调查的样本量相当，该调查此后更名为季度劳动力调查（Quarterly Labour Force Survey, QLFS）。1994年12月起，北爱尔兰的调查转为全季度周期，与英国其他地区保持一致，至此QLFS覆盖全英国（不过英国数据档案馆仍留存有部分额外的北爱尔兰LFS年度数据集）。更多关于QLFS背景的信息可查阅相关文档。

纵向数据
LFS会将每个样本家庭保留五个连续季度，每季度替换五分之一的样本。该调查最初旨在生成横截面数据，但如今已将每个个体的相关数据进行关联，以提供纵向信息。纵向数据包含两类关联数据集，均通过加权方法调整无回应偏差。两季度数据集关联连续两轮调查的数据，而五季度数据集则覆盖一整年（例如2010年1月至2011年3月，含首尾时段），包含全部五轮调查的数据。完整的纵向数据序列可追溯至1992年冬季。通过关联记录构建纵向维度，可获取不同劳动力分类（就业、失业与经济不活跃群体）间随时间变化的总流动信息，进而详细分析在各类群体间流动的人口情况。此外，纵向信息有助于监测政府政策的实施效果，可用于追踪受特定政策举措影响人群的后续活动与境况，并与其他人口群体进行对比。不过，纵向数据关联过程中可能存在方法学问题，导致数据失真。英国国家统计局（Office for National Statistics, ONS）仍在持续研究此类问题，并建议对结果的呈现需谨慎处理，必要时需在输出结果中附带警告说明。

LFS文档
档案馆配套LFS数据集的文档，主要包含各卷最新版用户指南与对应年度的调查问卷。但英国国家统计局会定期更新相关卷册，因此建议用户在开展分析前，先查阅英国国家统计局的劳动力调查用户指南页面（https://www.ons.gov.uk/employmentandlabourmarket/peopleinwork/employmentandemployeetypes/methodologies/labourforcesurveyuserguidance）。对于旧版QLFS的使用者而言，这一点尤为重要，因为用户指南中的信息与指引可能已随时间发生变更。

源自QLFS的附加数据
档案馆还留存有更多QLFS系列数据集：最终用户许可（End User Licence, EUL）季度数据、安全访问数据集、家庭数据集、为欧盟统计署编制的季度、年度与特设模块数据集，以及部分额外的北爱尔兰年度数据集。

变量DISEA与LNGLST
曾因2017年4月至6月与2017年7月至9月间出现明显的数据不连续性，被英国国家统计局暂停的A08数据集（残疾人劳动力市场状况）现已恢复可用。鉴于该不连续性问题及现阶段调查结果尚未明确，在比较2017年4月至6月与后续时段的数据时需格外谨慎。此外，用户需注意，本项估算未进行季节调整，因此部分季度间的变化可能源于季节因素。英国国家统计局将于2018年11月发布2018年7月至9月的估算数据，届时将提供关于历史数据比较的进一步建议。一篇阐述迄今为止开展的质量保证调查的文章，可在英国国家统计局方法论网页（https://www.ons.gov.uk/employmentandlabourmarket/peopleinwork/employmentandemployeetypes/methodologies/analysisofthediscontinuityinthelabourforcesurveyydisabilitydataapriltojune2017tojulytoseptember2017）查阅。若对A08数据集有任何疑问，请发送邮件至[e-mail]。