R (on the application of FDA and others) v Secretary of State for Work and Pensions and another [2012] EWCA Civ 332, [2012] All ER (D) 139 (Mar)
It was permissible, within s 150 of the Social Security Administration Act 1992, to use an index compiled on the basis of the geometric mean, rather than the arithmetic mean, for determining whether, and to what extent, state pensions and other annual payments had lost their value in relation to the general level of prices.
It would have required clear exclusionary or limiting words in s 150(1) before it could fairly be concluded that Parliament had intended that such an index could not be invoked by the secretary of state for the purposes of that section. There were no such words. Section 150(1) left it to the secretary of state to select the method by which he estimated whether, and if so to what extent, certain benefits and pensions had lost their value in relation to the general level of prices obtaining in Great Britain during a particular year. Provided that he acted rationally and took all appropriate, and no