There recently appear a vast amount of R&D collaborations among firms in supply chains,but this field is under-researched.This paper studies strategies and effects of bargaining power and knowledge spillovers at firm level when cooperation and competition coexist in aligned R&D within 13 supply chains.Differently with the main results about horizontal collaboration,a higher level of R&D investment and production can be achieved in aligned R&D although spillovers are low,compared ...