first constraint (8b) balances the sales of fresh white seedless grapefruit in the domestic and

export markets plus the quantity of white seedless grapefruit processed into juice against the

production of white seedless grapefruit (Z,). The second constraint (8c) enforces a similar

balance for red seedless grapefruit; The third constraint (8d) balances the production of juice

against the sales of juice in the domestic (Qs) and export (Q6) market. The time subscript t has

been omitted from (8a)-(8e) for simplicity.

 The quadratic programming model (8a-8e) is solved for a particular season. Equilibrium

price and quantity are established in each of the six markets. Adjustments to these prices are

made to account for the cost of harvesting, hauling, and packing. Ultimately, on-tree prices for

white seedless and red seedless grapefruit are determined. These prices are used to update the

three-year moving average of on-tree prices and new plantings of each variety of grapefruit are

projected. The existing tree inventory is updated via equations (3) and (4) and production for

the next season is re-estimated through equation (2). The model is solved in forward recursive

manner through time.

 For the specifics of the data used to empirically specify the quadratic programming

model, see Pana (1991). The major difference between the model used in that study and the

model used herein is that the present model is validated using the 1991-2 season.


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