In March, over fifty members and guests were addressed by Mrs Bridget Rosewell OBE, a founding partner of the Volterra Partners consultancy and a member of the National Infrastructure Commission. She posed the question, “Infrastructure and the Economy: What can we prove, if anything?” The National Infrastructure Commission has been set up to provide an assessment of infrastructure needs looking 30 years ahead and covering energy, transport, communications, water, waste, flood and sewerage.  The criteria for such an assessment are to support sustainable economic growth, quality of life and the environment – no mean challenge, not only in looking forward but also in assessing how infrastructure has supported the economy in the past. In a wide-ranging expert review, Bridget Rosewell argued that we need to identify investments that will be worthwhile in most states of the world that we can imagine, investments that will be viable in a proportion of such states and those which will only work in some states, but which will have a large payoff if they do.