Chapter 3


Some crops are more susceptible to differing weather conditions and cyclical variation can
be reduced by careful choice of crop and diversification. However, some countries have
much more variable climate, resulting in differing variability for the same crop in different
countries. Table 3.3 shows the variation in maize production over time for a number of
different countries. Care must be taken not to attribute all variation in crop output to weather
variation. Policy changes and civil strife can also affect the level of crop output. Adopting
different technologies, such as the use of irrigation and drought resistant seeds can also
reduce output variation.

Figures are given for growth rates as well as the CV of production for each country, because
for a true comparison of variation, series should be compared net of growth rates. All things
being equal, a higher growth rate will result in a higher CV. Of the three countries with
highest CVs, Tanzania, France and Zimbabwe, growth rates are an important factor in
increasing the CV in the first two, but Zimbabwe's CV shows a very high level of year on
year variation. So to do South Africa and Zambia. However, Burundi and Kenya both have
relatively low CVs, taking into account their respective growth rates. The USA has similar
variation to Kenya, though it is likely that output variation in the USA is policy-induced
rather than climatic in nature.

Time series can be decomposed into the seasonal element, the trend element, the cyclical
element and a random element. This allows for a more complete analysis of expected
variation both within year and between years. It is easier to do this on monthly figures,
where a seasonal pattern can be identified, both in terms of output and price levels. It is very
much more difficult to decompose a time series where there is no seasonal element.
The reason for trying to understand better cyclical variation at the national level is to allow
for better planning for poor harvest years. Most households would not be in a position or
wish to store against annual variations in output. However, governments can, and often do.
One way is to try to store domestically an amount of grain to cover the average shortfalls in
poor years. However a cheaper and often more effective way to plan for cyclical shortages is
simply to assess the time lag necessary between ordering grain imports and their arrival in
the port, and ensure that adequate grain is stored on buffer stocks to cover that time period.
In other words, if commercial imports take three months to arrive in port from the time of
ordering, a risk averse government will ensure that it maintains a buffer stock of three
months' national consumption.

4.3 Household coping strategies under stress

The third type of food insecurity to be discussed is transitory or temporary food insecurity.
Sudden shocks which lead to food insecurity can be transitory in the sense that in the next
time period, the situation reverts to normal and provided the household can survive that
shock, then there is the possibility of life returning to normal, though this is not inevitable.
The classic shocks of this nature are drought, flooding and pest attacks causing crop failure.
However, loss of employment or the illness of a wage-earner could also fall into this
category.


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