Refining the measurement of consistency in sentencing: A methodological review

The importance of improving consistency in sentencing has been underscored by institutional reforms in a number of jurisdictions. However, the effectiveness of these policy changes has not been clearly measured. To a certain extent this is due to the methodological confusion reflected by the multiplicity of methods that have been used in the study of consistency in sentencing. Here we review and categorise all of the quantitative methods that have been used to measure consistency in the literature. Our classification differentiates methods based on characteristics such as their robustness, the type of data they require, or whether they are amenable to comparisons in time or across jurisdictions. In this way the paper has a twofold contribution: it simplifies the implementation of future empirical analyses on consistency and facilitates their critical interpretation.