Why do potato prices fluctuate so much?
Product can hardly be stored for more than a year
Product not worth transporting because it is heavy goods
little substituted product: consumers do not switch to substitute products to any great extent when potatoes are scarce and expensive, but also hardly consume more when goods are available in abundance and at low prices
Free market price formation with different price elasticities depending on the supply situation
Potato cycle: Although potato producers react to the prices of previous years with a relatively increasing or decreasing acreage around the falling trend, the weather-related yields per hectare are more decisive for the harvest volume.
The consequence in certain individual years: Weather-related small harvests are more than compensated for by a disproportionately high price increase (= King's rule)
. . . and vice versa, with producer prices so low that occasionally the harvest costs alone (approx. 30 % of total costs) are higher than the value of the goods to be harvested.
