The decisions and ideal points of British Law Lords

Policy-sensitive models of judicial behaviour, whether attitudinal or strategic, have largely passed Britain by. This article argues that this neglect has been benign, because explanations of judicial decisions in terms of the positions of individual judges fare poorly in the British case. To support this argument, the non-unanimous opinions of British Law Lords between 1969 and 2009 are analysed. A hierarchical item-response model of individual judges’ votes is estimated in order to identify judges’ locations along a one-dimensional policy space. Such a model is found to be no better than a null model that predicts that every judge will vote with the majority with the same probability. Locations generated by the model do not represent judges’ political attitudes, only their propensity to dissent. Consequently, judges’ individual votes should not be used to describe them in political terms.