NUTRICIÓN: APARATOS CIRCULATORIO Y EXCRETOR

Here, the following question is raised. Are the spatial variations of maize production in 2008/09 reflective of the trends in the country or not? To address this question the study compares household per capita maize production in the three regions of the country. Available data indicate that the average landholding is evenly distributed throughout the country as indicated in Figure 4.5 below.

102

Figure 4.5: The distribution of mean landholding size in Malawi (2006/07)

Source: National Statistics Office (2008a, p. 14)

In all the three regions, the majority of households own land between 0.5 and 1.0 hectare, a situation which has “mostly remained unchanged during the past ten years” (National Statistics Office, 2008a, p. xi). As pointed out earlier, the majority of smallholders use their land for maize cultivation. This implies that comparing per capita household maize production at regional level would yield statistically unbiased results.

Firstly, a test for normality is conducted to guide the study as to whether parametric tests can be used. Results, as indicated in Appendix 4, suggest that maize production at regional level is not normally distributed. In view of this, the Epanechnikov Kernel density39 is employed in order to compare household per capita maize production in the three regions of the country. This test is premised

39 _{According to Silverman (1986), the Epanechnikov Kernel density is the most effective method}

with regard to reducing the error when estimating the actual density. 0 5 10 15 20 25 30 35 40 <0.1 0.1-0.199 0.2-0.499 0.5-0.999 1-1.999 >2 Av ear ge lan d h o ld in g (% ) Hectares North Centre South

103

on the assumption that data for each of the regional maize output (1964-2008) is nonparametric and has a probability density function , i.e.:

(4.8)

Silverman (1986, p. 12), argues that if “ ” then a kernel density estimator can be developed as follows:

(4.9)

where, is any given small number (band width), is the number of 40 _{that fall}

in the range , is the point where the density is estimated and is the weight (Kernel) function whereby:

(4.10)

Figure 4.6 below is a graph of the Epanechnikov Kernel density estimates indicating the regional household maize production per capita. A vertical line reflecting minimum national per capita maize requirement of 0.17 metric tonnes is added to the graph. According to government studies, an average household of about five to six members requires a minimum of 0.17 metric tonnes of maize per head annually (Australian Centre for International Agricultural Research, 2010; Mkandawire, 1999).

40

104

Figure 4.6: Epanechnikov Kernel density estimate of regional per capita maize production in Malawi (1964-2008)

Data source: Ministry of Agriculture and Food Security (various issues)

The distributions indicate that each of the three regions has a number of households that fall on both sides of the national threshold. However, these numbers differ from one region to another. For the northern and central regions the modal distributions of per capita maize production fall on the right side of the national threshold. In the case of the southern region, the modal distribution is to the left of the national threshold.

In order to examine whether differences in regional maize production are statistically significant, the study employs the concept of notched box-and- whisker plot as developed by Haemar (1948), extended by Spear (1952) and popularized by Tuckey (1977). Each plot displays a five-number summary which includes “the minimum and maximum range values, the upper and lower quartiles, and the median” (Potter et al., 2006, p. 98) as indicated in Figure 4.7 below. According to McGill, Tuckey, & Larsen (1978, p. 14), “the notches

105

surrounding the medians provide a measure of the significance of differences between the values. Specifically, if the notches about two medians do not overlap…the medians are significantly different at a 95 percent confidence level.”

Figure 4.7: Side-by-side notched box-and-whisker plots of regional per capita maize production in Malawi (1964-2008)

The notches for household maize production in the south and the north overlap, implying that differences in their production medians are not statistically significant at 95 percent confidence interval. However, differences between household maize production in these two regions and the south are statistically significant with the latter being comparatively lower.

Figures 4.6 and 4.7 suggest that irrespective of similarities in average landholding, unlike the centre and the north, the majority of households in the south produce below the national minimum requirement and hence are likely to be more food insecure. These findings are similar to the ones obtained under local spatial analysis in section 4.3 which imply that spatial variations of maize production in 2008/09 are reflective of the national trends.

The foregoing implies that for the majority of households in the southern region, maize purchases are essential if their household food requirements are to be met. One would expect that the central region would be the main supplier of maize in

106

the southern region markets. However, studies have indicated that, as far as maize is concerned, there is very poor trade between the south and the rest of the country. The south mainly relies on informal cross-border trade with northern Mozambique for its maize supplies. According to Harrigan (2008, p. 247), “in the trade years 2001/2002 and 2002/2003 between a third and a half of southern Malawi‟s maize imports were informal and in 2002/2003 alone it is estimated that MT 223, 000 was informally imported from Mozambique.” Maize from Mozambique is usually much cheaper and its intra-year prices are more stable than maize from central and northern Malawi. This is because northern Mozambique employs extensive methods of maize cultivation and hardly uses fertilizer due to low population density and very fertile soils, respectively41.

Apart from price differences, cross-border trade in maize between southern Malawi and northern Mozambique is also influenced by cultural ties and proximity. Northern Mozambique shares boundaries with nearly all districts in the southern region and many people share traceable tribal roots which are usually reinforced by marriages across the two borders. With virtually no restrictions on border crossings between the two states, proximity makes informal maize importation from Mozambique easier and cheaper than getting it from the other regions which are comparatively further away. Figure 4.8 below indicates informal cross-border trading points between Malawi and its neighbouring countries.

41 _{Northern Mozambique’s sparse population density and fertile soils are partly due to the}

sixteen year old civil war (1977-1992) that killed and displaced many people and left vast land areas uncultivated.

107

Figure 4.8: Informal international maize trade: Cross border monitoring sites (2007)

Source: USAID & WFP (2010)

The map shows that of all 13 informal cross border points that Malawi has with its neighbouring countries, 11 are between southern Malawi and Mozambique. Studies have shown that buying and selling of maize dominates these cross border trade (USAID & WFP, 2010).

108