New evidence suggests that the context in which skills are developed could influence how effective they are in the workplace.
European researchers looked at the economic benefits of vocational education and training across six EU countries with different systems: three with strong apprenticeship systems and three where vocational training is mainly delivered in schools and colleges.
They found that the impact of skills on productivity was more pronounced in those countries where vocational education is based on apprenticeship training.
The researchers from Cedefop, the EU's vocational training centre, also found that vocational skills led to higher productivity when they were backed up by other skills developed through on-the-job training provided by employers.
"This kind of training is especially important in countries that lack strong apprenticeship systems, since many valuable skills are best learned, or can only be learned, in workplaces, not in full-time study settings," the report states.
It concludes that a mix of intermediate and higher-level skills are the most productive, and that countries should not rely too heavily on the expansion of higher education to bachelor degree level at the expense of intermediate skills development.