This is a collection of essays by leading economists surveying and assessing the contribution made to the development of economics in the 20th century by Sir Dennis Holme Robertson whose centenary was celebrated in 1990.Dennis Robertson and the real business cycle; Robertson, money and monetarism; D.H. Robertson and the monetary approach to exchange rates; Robertson and Keynes - three phases of collaboration; Robertson on effective demand and the trade cycle; the Robertsonian evolution.