A major problem in health economics is how to give a value to changes in health. This is the first book to present a comprehensive survey of the money measures that are used in such evaluations. The author defines the properties of these money measures, examining them in both a certain and a risky world. He evaluates available empirical approaches for the assessment of the value of health changes, and considers measures such as quality-adjusted life years (QALYS) and health-years equivalents (HYES).