be less accurate for the earlier index numbers. Too, the period selected
coincides with that presently used by USDA (1978), thus permitting more
direct comparison with their current index series.


 Base Period for Prices.--The arithmetic average price during the 12
 months from January to December, 1967, inclusive, was taken as a base
 price, or 100 percent for each commodity (Table 1). This period was
 selected to provide an index directly comparable with the United States
 farm price index. This period has a disadvantage for Florida in that
 citrus prices were out of line with other crop and livestock prices
 during the period. However, it is doubtful that one could find a 12
 month period of Florida farm prices when some commodities were not dis-
 advantaged when compared to all other prices received.


 Computation of Index Numbers.--The base price of each commodity in
 the index was multiplied by its quantity weight to obtain a base value
 which represents 100 percent. Then all current prices were multiplied
 by their respective quantity weights to obtain current values. The
 values were then added to groups with a final total for all commodities.
 To obtain the combined index number for each month, the current value.
 of all commodities for the month was divided by the base value. Thus
 for the month of May, 1976, the aggregate current value of $1,773,155,385
 was divided by the base value of $1,148,089,148 to obtain the combined
 index of 154.4 (Table 1). The 12 monthly indexes obtained each year were
 averaged without weighting for the annual index.
 Group index numbers were computed by dividing the current group
value by the base value of that group.


 Method of Handling Discontinuous Price Series.--Nineteen commodities
in the combined index do not have prices for every month in the year.
Because of their seasonal or perishable nature, they are sold only in
certain months (Table 2). Two other -commodities, type 62 tobacco and
sugarcane, have only annual price quotations. These crops are carried
in the combined index in months of no price quotations by inserting the
last price published every month until a new price quotation is available.
Thus for tomatoes, which are sold from November to June, the June price