This paper reports findings from a project undertaken for the Joint Information Services Committee (JISC) in the UK which explored the Economic Implications of Alternative Scholarly Publishing Models. The aim of the project was to examine the costs and potential benefits of the major emerging models for scholarly publishing, including subscription publishing, open access publishing and self-archiving. To ensure that cost-benefit comparisons can be made, analysis focuses on self-archiving models that include the certification and quality control functions necessary for formal scholarly publishing, namely (i) ‘Green OA’ self-archiving in parallel with subscription publishing and (ii) the deconstructed or overlay journals model in which self-archiving provides the foundation for overlay journal services. Adopting a formal approach to modelling the process and identifying activity costs, this paper examines scholarly communication life-cycle costs per article. It concludes that different scholarly publishing models can make a material difference to returns to R&D expenditure as well as the costs faced by various stakeholders. It seems likely that more open access would have substantial net benefits in the longer term and, while net benefits may be lower during a transitional period, they are likely to be positive for both open access publishing and self-archiving alternatives.