This article aims at studying who the best partners to innovate are for small and large firms. Considering the contradicting results of the literature on alliances and product innovation, we study the role of the size of the focal partner on these relationships. Using the French CIS04 database, we study the impact of cooperation with various partners on product innovation for small and large firms. Our results highlight that, for small firms, customers and competitors are the only partners increasing the likelihood of developing product innovation. If public research institutions are not significant, it appears that cooperation with suppliers is actually harmful for small firms. Regarding large firms, customers and public research institutions are the most attractive partners in terms of product innovation potential. The other partners (competitors and suppliers) do not increase or decrease significantly the likelihood of developing product innovation. Our results contribute thus to the emerging literature that emphasizes the specificities of alliances for small and large firms.
