Author : Habtemariam Kassa1, Robert W. Blake2, and Charles F. Nicholson
Introduction Policy makers and extension planners often assume smallholder mixed farming systems are incapable of
evolving fast enough to meet growing food demands and that livestock are relatively unimportant to household food
production or welfare (FDRE, 1994), except for intensive units. The resulting policy promotes substitution of either
intensive cropping or livestock production in place of the traditional mixed portfolio. Although widely promoted in the
Harar Highlands, farmers resist these recommendations in favour of more diverse and integrated systems with crops,
livestock, and non-agricultural activities. The contrast between what policy makers and development practitioners think and
what farmers do signifies misunderstanding about interactions that govern farmers’ behaviors. The evolution and potential
impacts of these agricultural systems on human welfare are also poorly understood, which precludes effective intervention
to help achieve farmers’ objectives. Understanding the crop-livestock subsystem is an essential part of the bio-economic
foundations of rural livelihood systems (Thornton and Herrero, 2001), which requires accounting its component stocks and
interactions (Ashley and Carney, 1999). Towards a goal of identifying through simulation “high leverage” interventions that
enhance system performance, our objective is to establish a conceptual model framework representing key elements of the
livelihood system structure.