1. Food Systems in sub-Saharan Africa: Variability, Vulnerability and Adaptation
Ruerd Ruben
Associate Professor WUR

2. Food Systems in sub-Saharan Africa
Central Issues
 LFAs: Heterogeneity and Vulnerability
 GEC-ICCD: Risk and Adaptation
 Linking production, expenditures & labour use
 Bio-economic farm household modelling
 Food chains and networks approach

3. Food Systems in sub-Saharan Africa
Extensive Growth
120,0 25
100,0 20
80,0 15
kilogrammes
=100
60,0 10
40,0 5
20,0
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
0,0
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
Decreasing Fertilizer Use
Increasing Cropping Area
Source: Ruben & Kuyvenhoven (2003)

4. Food Systems in sub-Saharan Africa
SSA Agricultural Development
Small increase food production
Decreasing food supply
Rising input costs
Lower food prices
Source: Ruben & Kuyvenhoven (2003)

5. Food Systems in sub-Saharan Africa
Topics and Approaches
Production options --> Crop simulation models
Income composition > Portfolio analysis
Risk coping strategies --> Livelihood analysis
Rural incentives > Bio-economic models
Bio-efficiency --> Chain analysis

6. Food Systems in sub-Saharan Africa
Poverty in LFAs
- Chronic Poverty +
Resource Degradation
- High transaction costs +
Low factor productivity
Source: Hazell & Ruben (2003)

7. Food Systems in sub-Saharan Africa
Economic potential of LFAs
Despite lower level, higher potential !
Source: Ruben & Pender (2004))

8. Food Systems in sub-Saharan Africa
Weather and Climate
 Irregular precipitation
 Concentrated showers
Source: Hengsdijk (2003)

9. Food Systems in sub-Saharan Africa
Critical Importance of sowing date
Crop type
Early sowing (quintal/ha)
Late sowing
(quintal/ha)
Wheat + Barley 12 6
Wheat 10 4
Barley 14 7
Teff 3
Finger Millet 13
Sorghum 18
Source: Hengsdijk (2003)

10. Food Systems in sub-Saharan Africa
yield
N-uptake
N application
plateau
N uptake
efficiency
Sustainable Intensification
 Complementarities
Labour & External Inputs
 Improving input efficiency
 Better yields
+ labour productivity  1 2 2 1 3 4
labour 4
The first and fourth quadrant remain the same but the third quadrant now represents the labour use efficiency of nutrient application. Combined with the nutrient uptake efficiencies and the yield response curves this gives us the relationship between labour input and yield. 3

11. Food Systems in sub-Saharan Africa
Bio-economic Farm Household modeling
Source: Kruseman, Ruben & Kuyvenhoven (2003)

12. Food Systems in sub-Saharan Africa
Consumption behaviour
Data derived from expenditure surveys (PRSP)
Based on utility maximization: Uc = f (Umax * (1-e) -Y
Engel curves for income-consumption relationship
Negative exponential utility function (declining U/Y)
Estimated for all income and consumption categories

13. Food Systems in sub-Saharan Africa
FHH Models: Supply Response to Policy Incentives (Mali)
--> Selection of feasible technologies and appropriate instruments
--> Win-win scenarios
Source: Ruben et al (in Lee & Barratt, 2001)

14. Food Systems in sub-Saharan Africa
Adaptive behaviour
Responses to decreasing rainfall:
less cotton, more arachide
more millet
Source: Dietz, Ruben & Verhagen (2004)

15. Food Systems in sub-Saharan Africa
Options for dealing with livelihood stress
Food acquisition
Direct/Indirect Food Intensification
Market exchange
Income/Activity Diversification
Off-farm employment
Social arrangements
Reducing food intake

16. Food Systems in sub-Saharan Africa
Strategies for dealing with micronutrient deficiencies
(searching for bio-efficacy)
Dietary diversification
Supplementation
Post-harvest processing
Fortification
Biofortification (through breeding) MN
supply
Uptake
efficiency MN
demand
Source: Slingerland et al., (2003)

17. Food Systems in sub-Saharan Africa
Further Perspectives
 Sustainable intensification
 Uptake efficiency (plants &
humans)
 Chain & network integration
 Multi-agency analysis
 Impact of Policy instruments