This study is concerned with the background and history of the SCP life situation index. SCP uses this index to track trends in the life situation of the Dutch population from 1974 to the present. Life situation is defined here as a combination of welfare and well-being. It covers a wide range of key social domains: health, participation (volunteering, social isolation, socio-cultural leisure activities, sport), housing situation, ownership of consumer goods, mobility and holiday patterns. The report describes precisely what the SCP life situation index is, how it originated, how it has changed over time and which conceptual framework is used to describe the results. In doing so, it looks among other things at the historical and international context and discusses the various choices that have to be made, such as the choice of domains and indicators (are the right domains and indicators included in the index?) and the way in which those domains and indicators are combined to form a single index. The report also looks at the question of whether using such an index is actually helpful. The report concludes with proposals for improving the index and the related conceptual framework