Highlights :

 Abstract :
Between 1950 and 1973, a process of absolute convergence was at work between the technological leader, the USA, West European countries and Japan. The catching up process between developed countries gradually vanished between 1973 and 1995. On the one hand, we had a revival of US labour productivity growth while, on the other hand most, European countries and Japan have registered a steep decline in their productivity. This paper nvestigates the source of these diverging trends. First we use an econometric test developed by Bai and Perron in order to find and measure breaks in productivity trends over the long term. It appears that although technological change played an important role in the US revival between 1995 and 2001 it is the low increase in employment between 2001 and 2007 than explains the continuing rise in productivity. The technological factor does not contribute either to explain the growth rate decline in other developed countries. Even if they were lagging behind the US in investing in these new technologies they had considerably increased their efforts. One crucial element in explaining these diverging trends is the change in the labour content of growth both in the US where it is declining and in most European countries where it increases. This article uses various data bases in order to find out the time and frequency in productivity trend breaks both at the macro-economic level and at the sectoral level. The most up to date data for 2008 tend to confirm our diagnosis of divergence.

 Keywords : Population active et emploi | Productivité du travail | Changement technologique | Croissance économique | Rupture de tendance

 JEL : J21, J24, O30, O47