The marketing margin, characterized as some function of the difference between retail and farm price of a given farm product, is intended to measure the cost of providiing marketing services. The margin is influenced primarily by shifts in retail demand, farm supply, and marketing input prices. But other factors also can be important, including time lags in supply and demand, market power, risk, technical change, quality, and spatial considerations. Topics for future research include improved specifications for margins and demand and supply shifters, retail-to-farm price transmission of retail demand changes, and impacts of vertical integration and policy interventions.
