In this paper we analyze how the technology used by downstream firms can influence input and output market prices. We show via an example that both these prices increase under a decreasing returns technology while the contrary holds when the technology is constant.
Jaskold Gabszewicz, J., & Zanaj, S. (2007). A note on successive oligopolies and vertical mergers (ECON Discussion Papers 2007/21). https://hdl.handle.net/2078.5/34666