This paper explores the issue of efficiency in English higher education using data envelopment analysis and stochastic frontier analysis to estimate an output distance function (which incorporates measures of both quantity and quality of teaching and research inputs and outputs) over a 13-year period. The study compares the efficiency estimates derived from various estimation methods, and uses the results to provide guidance to researchers, managers and policymakers on undertaking efficiency studies. The length of the study under consideration allows a preliminary statistical investigation of the effects on efficiency of merger activity in higher education.