Open Access initiatives, corresponding to unrestricted online access to peer-reviewed scholarly research are developed around the world and supported by research organizations and institutions. European Commission has launched in August 2008 the OpenAIRE (Open Access Infrastructure for Research in Europe) project, supporting Open Access in scientific information and research output. OpenAIRE connects institutional and thematic repositories, Open Access journals and Current Research Information Systems (CRIS), developing and promoting interoperability mechanisms for the efficient dissemination of scientific content, and monitoring uptake of funders� Open Access policies. In this paper we assess the economic sustainability of the OpenAIRE project. We use a Cost-Benefit Analysis framework in order to evaluate and compare the costs and benefits of OpenAIRE services, and provide explicit recommendations on the project�s economic efficiency and sustainable existence. OpenAIRE costs are explicitly documented in the market. OpenAIRE benefits, however, are not directly linked to specific market prices. As such these benefits can only be retrieved via the use of non-market valuation econometric methods. In this paper we apply a non-market valuation method based on the results of a �Choice Experiment�. Our approach is based on the elicitation of individual stakeholders� stated preferences and their aggregation over their relevant populations, yielding estimates of the Total Economic Value (TEV) generated by OpenAIRE. To this end, we identified, prioritized and mapped the relevant stakeholders based on their familiarity with Open Access and OpenAIRE, and their willingness to engage with similar initiatives. Then, we created two different questionnaires for researchers and non-researchers, using a full preference ranking approach. For the researchers we used budget reallocation from teaching/research budget and from infrastructure/library/administration budget. We estimate that the average OpenAIRE stakeholder�s Willingness to Pay (WTP) is 1763.13 �/institution/year for the basic services provided by OpenAIRE. OpenAIRE stakeholders prefer to have more interoperability between research platforms and research output, better access to scientific results and compliance to Open Access mandates. Applying a cost benefit analysis, we estimated that the net social benefits for the basic services for 15 years add up to 5,724,000 �, which are at least 5 times higher than costs� present value. Moreover, using Jone�s R&D based model, we estimated the potential R&D effect from research suggests even larger benefits in the long run with a Benefit/Cost ratio of 71.82, 95.75 and 115.58 for 50, 75 and 100 years, respectively. Risk analysis supports the robustness of the study�s results under different assumptions on future costs and benefits. Subscriptions based on the estimated WTP and cost, institutional subsidies and public awareness were our main recommendations for the sustainable operation of OpenAIRE. This study contributes to the literature on monetary valuation of the benefits and costs of Open Access to scientific knowledge.
