The share of resources allocated to food marketed through supermarkets and their marketing channels has grown at an unprecedented rate in lower income countries during the 1990s. The implication is that the evolution of supermarkets cannot be viewed in isolation of the broader economic general equilibrium forces giving rise to a middle class, nor can this process be viewed in a static context. Our dynamic model captures, in an obviously aggregative way, the marketing channels that require resources to: assemble inputs for farmers, produce raw agricultural output, assemble, process and add value to, and market the final products to retail establishments in the long run.