index-based insurance, also known as index-linked insurance or, simply, index insurance, is primarily used in agriculture. because of the high cost of assessing losses, traditional insurance based on paying indemnities for actual losses incurred is usually not viable, particularly for smallholders in developing countries. with index-based insurance, payouts are related to an “index” that is closely correlated to agricultural production losses, such as one based on rainfall, yield or vegetation levels (e.g. pasture for livestock). payouts are made when the index exceeds a certain threshold, often referred to as a “trigger”. index-based insurance is not therefore designed to protect farmers against every peril, but only where there is a widespread risk that significantly influences a farmer’s livelihood. many such indices now make use of satellite imagery.