This is a case study for Principle Q1: Suitable data sources.
Legal aid statistics for England and Wales are published quarterly by the Ministry of Justice (MoJ) and draw on a range of Legal Aid Agency (LAA), an executive agency of the MoJ, administrative data sources. Legal aid statistics were first published independently as Official Statistics in 2013, and were awarded National Statistics status in 2016.
Legal aid is a complex area and the statistics report on a variety of criminal and civil legal aid schemes, including police station attendance and civil representation. The statistics provide an extensive evidence base on the legal aid system, but the constraints of using administrative data from LAA systems means that there are some things they do not measure precisely, or at all. To enable user understanding, MoJ publishes a comprehensive Guide to Legal Aid Statistics in England and Wales. The user guide includes considerable detail about operational context in which the data are recorded and case studies to show the types of cases where legal aid would be granted and how this would be shown in the statistics
The guide also provides a summary of the team’s professional judgments around the robustness of each data source and, more generally, a clear steer on the sort of comparisons that the overall statistics allow (e.g. volume and expenditure levels by scheme) or do not permit (e.g. the number of clients or precise geographic distribution of legal aid clients). A detailed account of the individual data sources used is further detailed in a separate ‘index of legal aid data’. The index and user guide both include a flow diagram which presents the data sources for each of the legal aid schemes.
Many legal aid data sources are subject to minor revisions within each quarterly update from new information being included, or previous information being amended, on the underlying systems. These revisions are clearly flagged in the quarterly statistics.
The legal aid statistics team were embedded in the LAA until recent years and maintain close links with LAA colleagues, including those responsible for the management and supply of the administrative datasets. These relationships help provide additional insight into the detail of the data sources used and any changes to these. A recent example of this was when a new provider contract for telephone advice services led to a discontinuation of a published time series on costs. These changes were explained by LAA colleagues and subsequently reported in the statistical series.
There have been numerous other enhancements to the statistics over time, which are also clearly documented in the user guide timeline, and which have continued to improve the comparability and transparency of the data sources used to produce legal aid statistics.
This example shows how the legal aid statistics team within MoJ ensure that the LAA data they draw on is appropriate for statistical purposes by having a thorough understanding of the operational context within which the administrative source data used to produce the statistics are collected, and by maintaining close links with LAA data suppliers. It also shows the considerable lengths that the statisticians go in explaining the relative strengths and limitations of the various data sources used to ensure the appropriate interpretation of the official statistics, including explaining the impact of changes or revisions to data sources and administrative systems over time.