Sheep as capital goods and farmers as portfolio managers: a bioeconomic model of Scandinavian sheep farming

A model analyzing the economics of sheep farming is formulated. The basic idea is simple. Sheep are capital and they are held by farmers as long as their capital value exceeds their slaughter, or meat, value. Farmers are therefore portfolio managers aiming to find the optimal combination of different categories of animals. Yields are compared with the yields from other assets. The model is formulated within a Northern Scandinavian economic and biological setting with a crucial distinction between the outdoors grazing season and the indoors season, and with adult sheep and lambs being different categories. In the first step, the management problem is analyzed with only the meat income of the farmers taken into account. In the next step, income from wool production is considered as well. The analysis provides several results that differ from standard harvesting theory.