The analysis of the role of services in the economy began in the nineteenth century with the development theory of economic stages by the German historical school. The traditional Fisher-Clark thesis attempted to explain the secular shift of employment towards the tertiary sector by combining two elements: the relative increase in demand for services with growing per-capita income of private households and the underlying trend of service productivity to rise more slowly than other parts of the economy. The post-industrial model and its supposed transformation process, where employment in services is substituted for manufacturing and alienated labour is replaced by undivided labour with personal contacts between producer and consumer, is an over optimistic vision of the future. Economic policies which promote service employment growth have to foster the conditions for growing physical and human investments, for greater international competitiveness, greater mobility and smoother sectoral and regional adjustments.