Retail sales of fluid cow’s milk are decreasing while those of plant-based milk analogues are increasing. In this study, we model the relationship between households’ purchases of both types of products and perform simulations. Results show that growing consumer demand for plant-based products is causing cow’s milk sales to decline somewhat faster than otherwise. However, plant-based products are not a primary driver of sales trends for cow’s milk. The decline in cow’s milk sales is substantially greater than the rise in sales of plant-based analogues.