Variability in crop yields as a cause of failure among peasant farmers

Year‐by‐year variability in crop yields is known to prejudice the survival of peasant farmers, but there is little in the published literature to quantitate the effect. A simple computer model has been used to demonstrate that the ill effects of year‐by‐year variability fall mainly on the poorest farmers with little buffer stock or excess yields over their basic needs. When the year‐by‐year variability in the crop yield is 20% (coefficient of variation), a moderate level of buffer stock gives a high level of safety. When the variability rises to 40%, much larger buffer stocks are needed and these achieve only a lower level of security. These results suggest that a review of data on the levels and effects of year‐by‐year variation in crop yields should provide valuable information on methods of increasing security of peasant farmers.