The revival of interest in using models for developing
countries for planning and policy advice makes it desirable to draw
lessons from past experience. Simple models, focussed on specific
issues, are to be preferred to large and comprehensive models. More
empirical research is needed on supply and production functions for
developing countries. Not statistical criteria but developmental
considerations must determine the conclusions to be drawn from models.
More explicit explanations of assumptions and modesty in presenting
results of modelling work to policy makers are desirable.