Dear Joe

Use of statistics in judicial review reform

Thank you for your letter on 20 April 2021 setting out your concerns about analysis in the Independent Review of Administrative Law (IRAL) report. You asked us to investigate the accuracy of an analysis of the success rate of Cart judicial reviews, which found that only a very small proportion (0.22%) of reviews are successful.

It is not usually within our remit to comment on the use of statistics in independent reviews. However, we agree that the main assumption that underpins the analysis – that all unreported Cart cases are failures – is overly simplistic, because we know that some unreported cases have successful outcomes, as highlighted in your blog post as well as in articles by Joanna Bell and Mikołaj Barczentewicz. It would have been helpful if the report had discussed the limitations of the analysis, including the rationale for the assumption.

The blog post by Dr Joanna Bell, mentioned in your letter, emphasises the lack of data. She suggests that the most useful reform may be to “compile and make accessible fuller information” on the judicial review process. We support her call for better data on this topic and will raise the issue with the Ministry of Justice (MoJ).

My team spoke to the MoJ team that supplied the data on judicial review applications to the IRAL panel that informed part of the panel’s analysis. MoJ has agreed to review how the data are presented in its publications and the associated caveats. It also said it would examine the possibility of collecting improved data in the longer term.

I am copying this letter to Jo Peacock, Chief Statistician at MoJ, and Prof Jane Hutton, Chair of the Royal Statistical Society’s Statistics and Law Section.

Yours sincerely


Ed Humpherson
Director General for Regulation


Related Links:

Dr Joe Tomlinson to Ed Humpherson: Use of statistics in judicial review reform