We develop a simple theoretical model of a long term buyer-supplier relationship with non-contractible buyer specific R&D investment, and derive predictions on the effects of trust and competition on suppliers' investment and buyers' procurement strategies. We address these issues empirically...

Introduction / Nicola Dimitri, Gustavo Piga and Giancarlo Spagnolo -- The variety of procurement practice : evidence from public procurement / Laura Carpineti, Gustavo Piga and Matteo Zanza -- General strategic principles -- When should procurement be centralized? / Nicola Dimitri, Federico Dini...