Jacques Lesourne was formerly a professor of economics and industrial statistics at France’s National Arts and Crafts Conservatory. He is a member of the French Academy of Technology and the author of, notably, Démocratie, marché, gouvernance: quels avenirs? (2004), Vérités et mensonges sur le chômage (1995), Le Modèle français: grandeur et décadence (1998) and Les Crises et le XXI^e siècle (2009).

Anxiety about the problems facing the twenty-first century has spurred an interest in prospective studies, especially among the younger generations who wish to understand possible future scenarios. But the study of these scenarios requires the ability to distinguish the timeframe in which the various elements exist (as in deciphering a musical score). Prospectivists must therefore isolate significant events; detect possible breaks; and identify the processes of economic growth, social transformation, technological advances and increased knowledge. In addition, they must analyse the characteristics of various time periods regarding trends, economic fluctuations, political alternation and traumatic historical periods or centuries.
How to compare and contrast different time periods when analysing future scenarios? How far into the future can such scenarios reach? How to distinguish between the sparkle that will die out and the lightning flash that announces the end — or the beginning — of the storm? These are fundamental questions for contemporary prospective studies.

• Instead of describing a ready-made methodology, the author, an eminent prospectivist, shows us how to picture the future.