ABSTRACT
This chapter examines the types of conditions in the economy and within the system itself, which might alter the constraints of the planning model by varying over the adoption period. The survey provides data on the types and quantity of food being supplied from each crop activity identified as sufficiently important to warrant independent representation in the planning model. As with labor supply constraints, the observed level of capital outlay is adopted as an initial constraint on the planning model. The producer prices of export crops will ultimately be dependent on the world market, which is exogenous not only to the farming system in question but also to the economy, and as such is out of the control of government. The main source of changes is policy, both for internal prices and for institutional development. While changes of either type might be dramatic, given political stability, basic policy objectives are usually long-term.
