This article presents a new decomposition of unit labour costs into compensation per worker and labour productivity, which, in turn, is decomposed into e ffciency gains, technical progress and capital deepening. Data for Western European countries and the US show that the evolution of labour productivity components counteracts the deterioration in countries' cost competitiveness caused by increases in nominal wages. The policy implication is that e fforts aimed at reducing nominal labour costs should be accompanied by policies fostering capital deepening. Further improvements in countries' cost competitiveness can be achieved by enhancing efficiency gains and technical progress, which has been mostly negative during the period under study.
