The thirty years that followed the Second World War were Europe's ‘Golden Age’; commonly known in France as ‘les Trentes Glorieuses’. At that time, the countries of Western Europe were experiencing the fastest growth rates in their history. Between 1950 and 1973, their GDP per capita grew at an average rate of 3.8% per year, compared with 1% between 1913 and 1950 and less than 2% throughout the twentieth century. Expansion was pronounced in Germany (5%), somewhat less so in France (4%) and considerably less so in the United Kingdom (2.5%) – where, however, the level of income was higher than in the major countries of continental Europe at the start of the period. In one generation, Europe managed, if not to catch up with, then at least to draw closer to the United States, where growth, admittedly strong (2.2%), was bound to be slower. A European's average income, which barely exceeded half an American's in 1950, was getting on for three-quarters in 1973. Europe had definitely entered the age of plenty and mass consumption. Economic development was even more spectacular in Japan which, thanks to average growth of 8% per year, became the second world economic power by 1973. By then its GDP was one and a half times higher than Germany's, despite having been only in sixth place, behind Italy, in 1950.

What should this outstanding post-war expansion be attributed to?