POSSIBILITIES AND LIMITS OF MODELLING THE DEVELOPMENT OF HORTICULTURAL FARMS BASED ON ACCOUNTING DATA

Often the evaluation of policies, regarding the horticulture sector in Germany, is carried out by analysing official statistics and deriving general qualitative recommendations. In order to generate trends of future developments of horticultural sectors in more detail, quantitative farm models based on individual accounting data from horticultural farms has been designed and implemented as a computer model. To capture the broad variety of farms in a horticultural sector, several different structured enterprises, which correctly reflect the investigated sector, run through the model. For all farms of a simulation the user determines external influencing factors of the forecast period as well as adjustment strategies.
Individual accounting data allow a direct description of developments of farms in a model. The validation of the model is limited to the range of the investigated values, because beyond these values distortions of results are possible. Increasing the forecast period also increases the deviation between the model results and the observed accounting data. The depersonalised accounting data available at the ZBG do not include information about individual production methods, cultivated plants and external influencing factors. This and the fact that farmers follow their own individual objectives, which is often not profit maximization, makes it difficult to interpret the single development of a farm in a sector. For individual farms a good agreement could be found between the model results and the real accounting data for a period of seven years. The results obtained by the developed model shows that the use of accounting data are applicable to reproduce medium-term adjustment strategies in horticultural farms on an abstract level.