In the euro area, according to OECD data for 2004, an average of 74% of those aged from 25 to 34 had attained at least upper secondary education, compared to only 45% of persons aged from 55 to 64. 26 However, so far investment in human capital in Europe is still clearly inadequate for a “knowledgeintensive” economy.
In 2003, the US annual expenditure on higher education institutions represented  24  European Commission, 2004, “A 3% R&D effort in Europe in 2010: an analysis of the consequences”, study prepared by the Research Directorate General of the European Commission. 25  Stiroh, K.J. (2000), “What drives productivity growth?”, Federal Reserve Bank of New York. 26  Unweighted average.