A system in which consumers pay farmers in advance for a share of their yield, usually in the form of weekly deliveries of produce.
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In its simplest form, CSA is a contractual agreement between a farm and a group of consumers variously described as "shareholders," "members," or "subscribers." Members purchase a "share" at the beginning of the season, allowing the farmers to plan production for a guaranteed market and providing capital up front to purchase inputs. Thus, shareholders pay the real costs of production and in this way contribute to the support of local, small-scale growers. Risks are shared: if there is a poor harvest, everyone gets less, not just the farmers. The cost of a share, decided in advance, takes into account estimated costs of inputs and labor and the standard of living of the farmers (Fieldhouse 1996; Groh and McFadden 1990; Kelvin 1994).