The strictly Orthodox Jewish population in the United Kingdom: Assessment of the census undercount using an alternative estimation system.

Strictly Orthodox Jews, otherwise known as Haredi, constitute about one-quarter of the total Jewish population of the UK. This population is growing very quickly. A religion question, first introduced into the census of England and Wales in 2001, is generally used to estimate the Haredi Jewish population. This paper claims that Haredi Jews have been severely and consistently undercounted in the census, leading to detrimental consequences for a proper understanding of the numerical dynamics of the UK's Jewish population as a whole and also compromised service provision. This paper develops an alternative estimation system that uses different types of administrative sources to quantify and correct for the census undercount of Haredi Jews. The paper proceeds to show that the undercount is not an exclusively 'Haredi problem': other ethnic and religious groups are also likely to be affected by it.