A yield stability index and its application for crop production

A good crop production technology should provide high yields under varying environmental conditions, i.e. keep yield fluctuations small. The magnitude of fluctuations is usually measured by statistical indicators of average dispersion, e.g. the standard deviation. However, while many small fluctuations are usually well tolerated by the farmer, an extreme yield may be a serious risk factor. The present research introduces a yield stability index developed which measures the frequency of extremely high and extremely low yields. The index is tested for 10 countries and 18 crops for 2004-2016, comparing it to 1961-2000, pointing out possible agricultural policy implications.