The graph clearly illustrates that for millet the price pattern was strongly linked to different
rainfall season. During this period the 1989/90 season was a poor production year, and the
prices after the harvest increased. The 1993/94 agricultural season was good, which resulted
in a decrease in prices following the harvest. The goat prices however remained fairly
stable, but there was a structural shift between 1994 and 1996. During this period there was
a transition from a fairly stable lower price to a fairly stable higher price. The result is that
the terms of trade during this period favored the millet producers in good production years
and favored pastoralists in bad millet production years.
5.3 Historical case studies
This section provides a series of interesting case studies of situations that have arisen in
the last few years in Africa. The examples are selected that illustrate key concepts or
situations. Each of the case studies will be organized in three steps. First, the price graph
that was initially observed will be presented. Next the steps that were used to interpret
and investigate the issue raised in the price graph will be presented. Finally, the actions
taken or follow activities are presented.
5.3.1 Devaluation in the Sahel (1994)
Observed price pattern:
The CFA, the currency in most West African countries, is tied to the French Franc. In
January 1994 the CFA was devalued. The graph below shows the behavior of prices of
domestically produced (millet) and imported (broken rice) commodities.
Time Series Analysis Grouped by Markets
for a Bamako market
1992/11992/31992/51992/71992/91992/11 1993/11993/31993/51993/71993/91993/11 1994/11994/31994/51994/71994/91994/11 1995/11995/31995/51995/71995/91995/11 1996/11996/31996/51996/71996/91996/11