In Live Long and Prosper?, a new eBook edited by David Bloom, AHPP director Karen Eggleston contributes the chapter "Understanding 'Value for Money' in Healthy Ageing," in which she advocates for and explains the concept of "net value of medical care," a metric that helps quantify the social value of spending on healthcare. Understanding value for money, Eggleston writes, is a way of "determining which services and technologies are unnecessary and which are of high value," a determination that is of increasing importance for aging societies, in which "spending for chronic diseases represents a large and increasing part of public and private budgets."