This article assesses the impact of retailer store brand products on manufacturer brand prices, profitability and consumer welfare in Boston's white fluid milk market. Estimates from a random coefficients logit demand model are used to specify and test a set of pricing games. Under the selected model, milk manufacturers are Stackelberg leaders to retailers, and store brand milks are procured by retailers at cost. The model is used to investigate counterfactual markets without retailer store brand milks. Counterfactual Simulation results indicate that store brands increase channel profits, retailer profits and consumer welfare, while having mixed effects on equilibrium retail prices.