  In a remarkable paper Frank Ramsey developed a framework in which each of these questions can be studied in a form that is precise and tractable enough to elicit answers (Ramsey, 1928). His approach was to apply the Classical-Utilitarian calculus to identify the best match from among attainable and desirable utility streams over time and across generations. Although very famous today, the paper had no initial impact. Some economists have attributed the lack of interest to the paper’s technical character. In answering the question he posed (“How much of a nation’s output should it save?”), Ramsey had to use the calculus of variations. There is no question but that few economists then knew the required technicalities. But it is difficult to imagine that there were no economists capable of learning the necessary mathematics had they wished to do so. The reason there was little interest in Ramsey’s paper lay elsewhere. In the years following the publication, a period now known as The Great Depression, the central economic problem in industrialised countries was to find ways to increase employment. Factories lay idle, as did people. The unemployment rate in Europe and USA was in the region of 25%. Policies that were needed then had to do with creating incentives for employers to hire workers. Even though there were controversies among economists on what those policies should be, no one doubted that industrialized societies were facing a problem of the short run. In contrast, Ramsey addressed a question involving the long run; and, so as to have an uncluttered problem to analyse, he took it as given that there is full employment at every date of both capital and labour.