i AN ASSESSMENT OF TOMATO PRICE VARIABILITY IN LUSAKA ...

- various channels through which tomatoes pass through before they finally reach
the retail outlets,
- volumes of tomatoes which are handled by the traders and their sources,
- lot sizes of tomatoes from the farmers, and
- type of first sellers of tomatoes in Soweto market; farmers or traders.
Volume data on supply areas was used to calculate total supply of tomatoes from each
area and also the total supplies channeled through the various identified marketing
channels.
Data on the lot sizes of tomatoes from different supply areas was used to estimate the
relative size of the farmers from these supply areas. The lot sizes from the farmers were
then categorized into terciles. Based on where lot sizes from a particular area fell in the
tercile groups, each supply area was categorized into three groups from the largest to
smallest implied farm size. The strength of using this approach of categorizing the supply
areas is that it gives a good estimate of the size of the majority of famers in a given area.
However, the down side to this approach is that it may underestimate or overestimate
actual sizes of the farmers in the supply areas. For instance, several small farmers may
have been categorized as large farmers merely on the basis of a few large lot sizes of
tomatoes they delivered to the market, or conversely, a few large farmers may have been
consistently delivering small lot sizes of tomatoes very often and were subsequently
categorized as small farmers. In general, however, the implied farmer size and resulting
classification of production areas that emerged from this exercise agree with the
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