Abstract: Identifying and weighing the efficiency functions and the anti-competitive consequences of the minimum Retail Price Maintenance（RPM）are important issues that need to be solved urgently in current antitrust theory and practice. The findings of this study show that when there is uncertainty in market demand and there is retail information asymmetry between the upstream manufacturers and the downstream retailers, there are three effects of competing manufacturers using RPM: the order improvement effect, which solves the problem of insufficient orders caused by market demand uncertainty; the tacit collusion effect, which prevents the colluding manufacturers from using information asymmetry to deviate from collusion and improves the stability of tacit collusion; the retail information effect, which prevents retailers from taking advantage of retail information to adjust retail prices. The specific impact of RPM on consumer welfare depends on the comprehensive comparison of the above effects. The greater the uncertainty in market demand, the smaller the degree of retail information asymmetry, or the weaker the product substitutability, the more likely it is that RPM will improve consumer welfare. The antitrust law enforcement agencies can classify and identify the motivations for RPM implementation according to the market demand uncertainty and the retail information asymmetry in the RPM implementation environment, whether retail prices change when low market demand occurs, and the attitude of manufacturers toward retailers’ price cuts. When a manufacturer may use RPM both for order improvement and for tacit collusion effects, the more substitutable the product, the more the law enforcement agencies should consider the anti-competitive consequences of the manufacturer’s use of RPM and implement relatively stricter scrutiny; otherwise, the law enforcement agencies should consider its possible efficiency features and take a relatively more tolerant stance on manufacturers’ use of RPM.

Key words: order improvement, tacit collusion, minimum retail price, market demand fluctuation, retail fluctuation