Positive social mobility benefits individuals in terms of personal advancement and the nation in terms of productivity. There are other social benefits aside. Education, including higher education, is widely understood to be a key contributor to social mobility. However, without a measure of universities' impact on social mobility it is difficult to assess their individual or combined contribution to this agenda and therefore to understand fully the value of university education to individuals, to the country and its taxpayers. The author sets out to identify a measure of universities' contributions to social mobility, combining the social distance travelled by graduates and the number of graduates transported. In this paper, Professor David Phoenix, the Vice-Chancellor of London South Bank University, proposes a new English Social Mobility Index (SMI). Incorporating the number of students from disadvantaged backgrounds and the distance they travel after they enter their higher education institution, the English SMI provides a new way of understanding the contribution of universities to social mobility. [Foreword written by Nick Hillman.]