In this blog, our Head Statistics Regulator for Crime and Security discusses the difficulties in understanding and interpreting crime statistics, and what OSR is doing to support producers in improving the quality of crime statistics for England and Wales.
Crime statistics are complex
Statistics on crime are widely used by politicians, governments, researchers, the media, and the public to try to understand the extent and nature of crime. Often, the questions that people want to know the answers to seem relatively straightforward: Is crime going up or down? What types of crime are most common? How reliable are crime statistics? Is it possible to measure all crimes? But answering these seemingly simple questions can be surprisingly difficult.
Understanding and interpreting crime statistics for England and Wales is complex. This is mainly because there are two data sources on crime: statistics from the Crime Survey for England and Wales (CSEW), a household survey of individuals’ experience of crime; and police recorded crime statistics, which capture the number of crimes reported to and recorded by the police. These statistics are published quarterly by the Office for National Statistics (ONS).
Both data sources have their strengths and limitations. The CSEW is the best source for understanding long-term trends in crime covered by the survey. This is because the survey methods have changed little in the last 40 years and the survey is not affected by changes to police crime recording practices or people’s willingness to report crime to the police. In addition, the survey captures crimes that aren’t reported to the police.
On the other hand, the survey doesn’t capture all crimes. For example, as it’s a household survey, it doesn’t capture crimes against businesses and organisations such as shoplifting. There are also challenges with the survey’s response rate, among other factors that affect the quality of the statistics, which led to the temporary suspension of their accreditation.
The police recorded crime statistics are a better indicator of police activity than trends in crime, because many crimes are not reported to the police. However, the statistics do provide insight on some higher-harm but less-common crimes such as homicide or knife crime, which the CSEW does not cover or does not capture well.
The police recorded crime statistics also cover a broader range of offences than the CSEW because the police also record crimes against businesses and organisations and crimes against society and the state, such as drug offences and public order offences. And the police recorded crime statistics are more granular than the CSEW statistics – the number of offences is broken down by police force area.
Due to these strengths and limitations, it’s important to look at both sources together to get the most complete understanding of crime in England and Wales. ONS’s Crime trends in England and Wales article provides a good guide on how to interpret both sources. It explains which source is best for which purpose. For example, it recommends using CSEW statistics to look at trends in fraud but recommends using police recorded crime statistics to look at trends in knife crime.
Our work on crime statistics for England and Wales
Crime statistics are a priority area for our regulatory work. It’s been a particularly busy period for regulatory work on crime statistics, and the coming months will continue to be busy. The quality of the statistics has been our main focus. One of the questions we’ve been focused on is ‘How reliable are the statistics?’.
Today, we published a detailed report on the quality of the police recorded crime statistics for England and Wales. Our review took stock of how data quality has improved since 2014, when we removed the accreditation of the statistics due to quality concerns. We found that police forces have made significant improvements to crime recording in the last ten years. This has given us greater confidence in the quality of the data. But we found some gaps in the Home Office’s oversight of police force data quality and in ONS’s communication of quality that we have asked to be addressed.
One subset of the police recorded crime statistics that we didn’t look at in our review is fraud and computer misuse statistics. That’s because the process for recording these crime types is different from that used for other crime types. We’re aware of the increased public debate about the scale of fraud and its impact on victims. To give this topic the attention it deserves, we’re doing a separate review of the quality and value of fraud and computer misuse statistics. We’ll publish the review later this year.
Like other UK household surveys, the CSEW has suffered from a lower response rate since the pandemic, which has impacted the quality of the statistics. We’re reviewing the quality of the CSEW statistics soon with a view to reaccrediting them.
We recognise that crime will be an important issue in the upcoming UK General Election. To support the appropriate use of crime statistics, we will be publishing a ‘What to watch out for’ explainer at the end of May that provides some tips and advice and sets out some of the common mistakes in public statements about crime that we have seen. It explains that it’s always better to look at the CSEW and police recorded crime statistics together to get an overall picture of crime in England and Wales.
Through this range of work, we are gaining a good understanding of the current state of crime statistics for England and Wales, helping us to support public confidence in the quality and value of the statistics and to continue to promote their appropriate use.
Related Links:
The quality of police recorded crime statistics for England and Wales