To cope with globalisation and other changes in the industry, in the last 20 years the Dutch Ministry of Agriculture has reorganised its system for education, extension and research considerably. It moved away from the concept of a linear process of innovation to that of an agro-innovation system. This paper describes the main changes. The paper argues that an evaluation of the changes is problematic. In an open economy where a large part of the public investments are targeted to reduce negative externalities of production (especially on environmental impact), a part of productivity is due to persons leaving the sector and income in farming is dependent on value added processes in its multinational cooperatives, causes and effects are hard to disentangle. The changes in the education, extension and research system cannot easily be evaluated by productivity analyses. Most research on this topic tries to develop methods for monitoring and evaluation from social learning or public administration.