As you scroll through an online newspaper, you see an article reporting that 6.3 million crimes were committed in the past year in England and Wales.
How do they know, though? — you think. It's not like the police can catch everyone who breaks the law!
An important aspect of criminal psychology is understanding how crime is measured. Can these measures be considered reliable and valid?
Even though the official statistics might be just the tip of the iceberg concerning crime, they are still of great importance for criminologists, policymakers, and the communities affected. In this article, we will discuss how we measure crime, the issues of crime measurement, and why it is crucial for criminal psychology.
- First, we'll introduce the concept of crime and the topic of how crime is measured in psychology.
- We will delve specifically into how crime is measured in the UK and cover the use of official statistics and self-report measures.
- Then, we'll see how it compares to how crime is measured internationally.
- Moving along, we'll examine how is crime rate measured.
- Finally, we'll evaluate the reliability of crime measures and examine how unreported crime is measured.
Analysing statistics, freepik.com
How is crime measured psychology?
To understand the approaches to crime measurement, we need to first define what we mean by crime.
Crime is an action or omission that violates the law.
How is crime measured: utility of crime statistics
Even though the law might differ across societies and times, it has an important role in protecting individual members of the community. We know that criminal activity is a factor that profoundly affects the well-being of victims of crime and society as a whole. Measuring crime can help us target and evaluate policies and interventions that aim to reduce it, which is why it is so crucial in criminal psychology.
Crime statistics also give us a glimpse into how crime rates change over time and across different regions; this allows us to identify the political and situational factors that contribute to crime.
At the beginning of the pandemic, certain crimes like robbery and theft decreased, while online theft increased, likely due to stay-at-home orders. Domestic violence incidents also appeared to increase.
Monitoring the type of frequently committed crimes can also help the police and legislators target their preventative interventions better.
Crime statistics can identify areas where crime is most concentrated, allowing the police to increase the monitoring of these areas.
How is crime measured in the UK?
In the UK, we distinguish two primary sources of crime statistics: official statistics produced by the Home Office based on reports from the police. And secondly, self-report surveys that ask citizens directly about their experience with crime.
Official statistics on crime
The official statistics on crime are published by the Home Office and are based on police recorded crimes. However, the picture they show might be inaccurate due to under-reporting.
Many crimes are never reported or detected by the police. Moreover, police reporting practices, so whether the police decides to put a crime on the official record, can also differ depending on the region and the officer.
Police-reported crimes can also inflate in response to specific police initiatives.
In the course of the pandemic, we saw a rise in police-reported drug-related crimes. This statistic was likely caused by increased efforts of the police force to target drug dealers and suppliers that previously operated unnoticed rather than an actual increase in drug-related crime.
How is unreported crime measured?
The number of unreported crimes, which is not included in the official statistics, is called the dark figure of crime. It is estimated that up to 40% of total crimes remain unreported in the UK. However, this figure will differ depending on the area. The most deprived areas are likely to have a higher rate of unreported crimes.
There are many reasons for a crime to be unreported. First, victims might be hesitant to report a crime if they fear the consequences of doing so or if they believe that the police won't be able to do anything about it. Moreover, many crimes reported to the police might not be officially recorded, for example, due to a lack of evidence.
The unreported crime iceberg, Alicja Blaszkiewicz, Vaia Originals
Self Report Measures – Victim Surveys
The Crime Survey for England and Wales (CSEW) was introduced to unveil the real crime statistics. The survey aims to gather information from a random pool of citizens about their experiences with different types of crime to create a more accurate depiction of crime prevalence and capture both the reported and unreported crimes.
According to police reports, 2% of the population of England and Wales was affected by domestic abuse before March 2022. Interestingly, the crime survey for England and Wales shows that the real number of victims is likely between 5 to 6%. This discrepancy is likely due to the under-reporting of domestic violence instances to law enforcement.
The data are collected from a number of randomly generated households to obtain a nationally representative sample. Then, participants selected to participate in the survey are contacted to arrange for an interview. Some of the questions asked may concern the participants' experience and perception of crime in the past 12 months.
Let's consider the advantages of victim surveys like the CSEW:
Victim surveys are generally considered more accurate than the official statistics because they can capture unreported crimes.
The data is kept confidential, meaning the individual respondents can't be identified once their information is collected.
In the case of the CSEW, the response rate is typically high, meaning that the selected participants agree to participate in the study. This is important for ensuring that the sample is representative of the population and avoiding respondent bias.
The CSEW investigation used interviews to get in-depth information regarding participants' experiences, freepik.com.
Self Report Measures – Offender Surveys
Self-report offender surveys ask respondents to disclose the crime they committed. The approach also has its limitations, as some offenders might under or over-report their criminal activity. These surveys are kept confidential to minimise potential bias.
The first longitudinal survey conducted in the UK that focused on both victimisation and offending was the Offending Crime and Justice Survey, which followed around 5,000 young people (age 10-25) from 2003 to 2006. The study uncovered that offending was very common among young people, and many of these offences were unreported. For example, the survey found that:
Half of the participants reported committing an offence.
The most commonly committed offence was assault, followed by drug-related crimes.
How is crime measured internationally?
There are several challenges to the international measurement of crime. Firstly, what is considered criminal can differ across different societies; this might become a problem when we want to compare or average the prevalence of crime across the globe. The International Classification of Crime for Statistical Purposes was introduced to address this problem; this system allows the classification of offences based on internationally agreed criteria.
Another challenge to creating international crime statistics is the difference in police reporting practices or the social norms influencing victims' decisions to report the crime.
Reporting of sexual crimes will be lower in countries where the victim would be shamed or punished.
One large initiative to measure crime internationally comes from the United Nations Office of Drugs and Crime. Their Surveys on Crime Trends and the Operations Criminal Justice Systems attempt to compile and compare crime statistics from the United Nations member states. This measure relies on both official statistics and victimisation surveys, where available.
International self-report victim surveys can also be used in international crime measurement. For example, the International Crime Victims Survey (ICVS) was conducted six times from 1989 to 2010 and collected data from respondents across 80 countries.
How is crime rate measured?
Just because one region has fewer crimes doesn't mean their crime rate is also lower. Crime rate indicates the proportion of the population affected by crime and allows us to compare the prevalence of crime between regions with varying population numbers.
Crime rate is usually expressed as the number of crimes per 100,000 members of the population.
The number of knife crimes reported by the police in 2022 before March 2022 was 49,027. To calculate the knife crime rate for this period, we need to divide this number by the population of England and Wales.
49,027/59,597,300 = 0.00082
This number tells us about the percentage of people impacted by knife crime. Now we need to multiply this number by 100,000 to get an estimate per 100,000 people.
Based on this Computation, the rate of knife crime in England and Wales is 82 per 100,000 citizens.
How Crime is Measured - Key takeaways
- Measuring crime can help target the areas where crime is most concentrated and evaluate policies that aim to reduce it.
- We distinguish two primary sources of crime statistics: official statistics produced by the Home Office, based on reports from the police, and self-report surveys, which involve asking citizens directly about their experience with crime.
- Police-reported crime figures might be affected by under-reporting. While self-report, victim and offender surveys aim to capture both the number of reported and unreported crimes.
- The national data (official statistics and victim surveys) is classified against internationally agreed crime criteria to compare and compile international crime figures.
- Crime rate is expressed as the number of crimes per 100,000 members of the population.
Explanations 
Textbooks 
Exams 
Magazine 
