Systembeskrivelse af bedriftsdelen i KRAM

CRAM is an aggregate holding based sector model of Danish agriculture. The model is developed at Unit of Economics (now dissolved) at KVL. The purpose of CRAM is to analyse how Danish agriculture reacts to various socio-political measures. CRAM describes Danish agriculture for every year over a ten year period. The model is made up of a series of sub-models, sketched in Figure ref.: MODELOPBYGNING. The submodels can be divided into two parts. One part consists of three sub-models; a farm animal, a crop and a sector sub-model. These three sub-models together make up that part of CRAM describing the internal relations for the agricultural holdings and the trading between the holdings. Therefore the three sub-models are referred to as one as the holding part in this paper. The other part consists of the market, the price and the investment structure of the sub-model. The latter three sub-models are solved between each of the ten years CRAM simulates. Therefore this part in the following is referred to as the middle period part of CRAM. The mutual connection between the sub-models to the middle period part is not further described in the paper. Instead the paper offers a detailed description of the connections between respectively the crop sub-model, the livestock sub-model and the sector submodel in CRAM. The purpose of the paper is to provide an understanding of the systematic correlation between the sub-models in the holding part of CRAM. The link between the sub-models is described, and a sketch of the respective exogenous and endogenous variables is outlined, which enters into the sub-models. An account is given of, which sub-models the variables enter into as endogenous variables (dependent variables), and which they are exogenous variables (independent variables) to. In connection to the choice of model type adhered to, other types advanced in agriculture all round the world are considered. Amongst others we could mention the Danish sector model ESMERALDA237, an econometric regionalised sector model in Danish agriculture. In respect of various types of mathematical programming models there are the Canadian sector model CRAM119, the Swedish sector model SASM120, the Dutch sector model DRAM118 and the Danish model FASSET130.