Enhancing the Measurement of Sentence Severity through Expert Knowledge Elicitation

Article (Journal of Legal Research Methodology)

Quantitative research on judicial decision-making faces the methodological challenge of analysing disposal types that are measured in different units (e.g. money for fines, days for custodial sentences). To overcome this problem a wide range of scales of sentence severity have been suggested in the literature. One particular group of severity scales that has achieved high validity and reliability are those based on Thurstone’s pairwise comparisons. However, this method invokes a series of simplifying assumptions, one of them being that the range of severity covered by different disposal types is constant. We undertook an expert elicitation workshop to assess the validity of that assumption. Responses from the seven criminal law practitioners and researchers that participated in our workshop unanimously pointed at severity ranges being highly variable across disposal types (e.g. much wider severity ranges were identified for suspended custodial sentences than for fines). We used this information to re-specify Thurstone’s model allowing for unequal variances. As a result, we obtained a new, more valid, scale of sentence severity.

Have the England and Wales Guidelines Influenced Sentence Severity? An Empirical Analysis Using a Scale of Sentence Severity and Time-Series Analyses

Article (British Journal of Criminology)


Presentation (British Society of Criminology)

Sentence severity has increased in England and Wales in recent years. The causes of the increase remain unclear. One possible explanation relates to the introduction of sentencing guidelines, which seem to coincide in time with the increase in sentence severity. To date, investigations of this hypothesis have been limited to simple exploratory analyses or to specific offences. We use a new scale of sentence severity – developed using Thurstone scaling and the participation of 21 magistrates – and time-series modelling to explore whether a causal effect can be attributed to seven different guidelines. We corroborate the existence of an increase in sentence severity, however, we do not find conclusive evidence pointing at the guidelines having caused it.

Exploring the Punitive Surge: Crown Court Sentencing Practices before and after the 2011 English Riots

Article (Criminology and Criminal Justice)

The English summer riots of 2011 resulted in the criminal justice system having to process an unprecedented number of offenders in a short timeframe. This study explores sentencing practice in the wake of the riots using the 2011 Crown Court Sentencing Survey. A multilevel model was implemented to specify the probability of receiving a custodial sentence for offences of commercial burglary. This model allows exploring differences in sentencing before and after the riots. An increased probability of receiving a custodial sentence in the post-riot period was identified. An increase in variability was also detected, changing from a state of almost perfect consistency to one in which substantial variation was observed between courts. Custodial rates for burglary increased to a level associated with more serious offences, thereby undermining the principle of proportionality. This, as well as the increased dispersion between courts, challenges other principles such as legal certainty and transparency.