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H. Review of Zambia's agricultural time series data
This section provides a review of the agricultural time series data available from two Zambian
government statistics units: the MAFF and the CSO. This review, which focuses on the crop and land
area statistics without reviewing the livestock data series, was accomplished by cataloguing the various
national surveys and supplying comments on the quality of the data sets. The comments are offered
with the admission that data sets are difficult to evaluate without corroborating data from other sources
or accompanying notes provided by the survey managers. Unfortunately, there are few comments in
MAFF or CSO publications concerning the data quality or technical notes describing survey designs.
No mention of calculating sampling errors for the CSO probability surveys was found in the
publication notes.
There are four sets of time series data that describe Zambia's agricultural sector: one generated
by the MAFF and three compiled by the CSO, the main data gathering agency for the Zambian
government. Each of these data sets is described below.
A. MAFF agricultural data series
Prior to 1983, the MAFF published three types of Agricultural Statistical Bulletins on a
consistent basis—monthly, quarterly, and annually. Both the quarterly and annual publications
provided various agricultural data for multiple years. These data, published at the national and
provincial levels, were obtained from parastatals such as the National Agricultural Marketing Board
(NAMBoard, the primary parastatal agency vested with the legal right to purchase most crops) and
the Tobacco Board of Zambia, and some private organizations and companies. As a result, only sales
are reported. Farm numbers, crop production, crop areas, and yields are not available for most crops
during these years. Livestock farm numbers are also not available prior to 1983.
The MAFF began its crop forecasting exercise for the entire crop subsector with the support
of the Food and Agriculture Organization (FAO) and the ZATPID I Project during the 1982/83
season. The purpose of this exercise, performed by the Statistics Unit (a unit of MAFF's Planning
Division) is to provide early warning information on the production of crops at the provincial and
national levels. The data series contain area, yield, and production estimates for the major crops. The
number of farms growing each of the crops were projected for internal use but not published. With
the initiation of crop forecasting, the MAFF continued to publish its annual bulletins, which now
contain more complete data series than the crop forecasts, but on an inconsistent basis. The last of
these "annual" publications covered the 1988/89 and 1989/90 crop years. Thus, the only data available
from the MAFF after 1989/90 are from their annual crop forecasts (table 8.2). Despite the lapses in
reporting, a fairly complete data series is available on the agricultural sector from the MAFF for all
crop years from 1970/71 onward.
The MAFF crop data are compiled by camp officers through their contacts with local farmers.
No sampling frame or probability survey techniques are employed. The data are categorized by size
groups: large (more than 20 hectares), medium or emerging (5-20 hectares), and small (less than 5