Technical coefficients for bio-economic farm household models: a meta-modelling approach with applications for Southern Mali

In recent years, different types of bio-economic models have been developed to support the analysis of the potential impact of agrarian policies on ch anges in land use, sustainable resource management and farmers' welfare. Mo st bio-economic models rely on series of discrete input-output coefficients for current and improved cropping and livestock activities, whereas mathem atical programming procedures are usually applied to analyse optimum alloca tive choice. Adequate procedures for the smooth integration of biophysical information into economic decision models are, however, not readily availab le. This article provides a new and comprehensive framework for the incorpo ration of technical input-output coefficients derived from agroecological s imulation approaches into bio-economic farm household models. Therefore, co ntinuous production functions are estimated for the production side of the farm household model, making use of meta-modelling principles. It is shown that meta-modelling offers considerable scope for improving the specificati on and behaviour of bio-economic farm household models. This procedure is a pplied in a farm household model developed for the analysis of farmers' res ponse to agrarian policies in Southern Mall. Results are presented for the behaviour of a typical household, focusing attention on the trade-offs betw een farm income and soil nutrient balances under free market conditions and with constraints on labour, capital and animal traction markets. The stabi lity and robustness of the model is analysed through a simulation of the im pact of higher input costs for land use and fertiliser applications. (C) 20 01 Elsevier Science B.V. All rights reserved.