Input price discrimination under passive partial cross ownership

Hu, Mizuno, and Song (Applied Economics Letters, 2021) compare the welfare effects of input price discrimination (IPD) and uniform input pricing (UIP) under passive partial ownership (PPO) where one downstream firm holds equity shares of its rival. This paper extends their setup to accommodate passive partial cross ownership (PCO) where each downstream firm holds equity shares of its rival. A common conclusion is that IPD improves welfare if the cost asymmetry is sufficiently low. Interestingly, this finding holds regardless of whether the more efficient firm is also the dominant partial shareholder. Indeed, it is found that the likelihood that IPD is welfare enhancing increases as firms become more asymmetric in terms of equity shares. However, the critical level of cost asymmetry differs under PPO and PCO, meaning that there are cases where IPD performs better in terms of social welfare under PCO but not under PPO, and vice versa. The main conclusion of this paper is that, compared to the PPO structure, PCO reduces the likelihood that IPD results in better welfare outcomes than UIP.