affected by a termination of fumigation is that destined for California, Texas, Hawaii, and

Arizona. Calculation of the economic impact of the loss of these markets to Florida grapefruit

producers is not simply the value of fruit which has been historically sold in these markets. A

superior approach is to estimate the effect on fresh Florida grapefruit prices under a ban on

Florida grapefruit sales in other citrus producing states. The model developed by Pana (1991)

can be modified to account for a ban and allow estimation of the price effects. Since

approximately one-half of Florida grapefruit is processed, it is also possible that a methyl

bromide ban will also affect the market for grapefruit juice.

 The mathematical model developed by Pana (1991) can be characterized as a spatial

equilibrium model with endogenous supply. Six markets for grapefruit products are delineated:

fresh white seedless domestic, fresh white seedless export, fresh red domestic, fresh red export,

domestic grapefruit juice, and export grapefruit juice. Price dependent demand equations for

each of the six markets were estimated. An important assumption of the model is that juice

from both white and red grapefruit are perfect substitutes3. Input to the model includes the

existing tree inventory for both white seedless and red seedless varieties. In each season, the

model computes the total availability of red and white seedless grapefruit by first multiplying

the average yield of a tree of a particular age times the number of trees in that age category.

Then the fruit from each age category is summed over all age groups giving total availability.

Next, the fruit is allocated across the six markets using a mathematical programming model.

This allocation determines the equilibrium price in each market. Next, an average price for



 'This assumption is probably not valid. The color of juice from white grapefruit is generally
preferred by processors, although significant quantities of red seedless are processed.

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