Food Demand and aflatoxin consumption in Malawi

A Quadratic Almost Ideal Demand System

Brent EdelmanIFPRI

Presentation outline

• Introduction• Methodology• Results and discussions• Concluding remarks

Introduction• Aflatoxins and related

mycotoxins are hazardous to human health (Soko, et al., 2014).

• Aflatoxins, a metabolite of Aspergillus spp., cause cancer, gene mutation and reduce immunity (Murphy et al., 2006).

Introduction

• Aflatoxin build up in crop outputs is mainly caused by keeping produce in damp areas, pest infestation, improper drying and poor handling techniques.

• Aflatoxins may build up as the crop is still in the field (Nkoka, 2007).

Introduction

• Considering that the poor consume lower quality foods aflatoxin consumption among them might be high (Monyo, et al. 2010).

• Aflatoxin consumption poses significant threats on household food and health budgets and overall economic growth.

• Aflatoxin and mycotoxin related cancers have also been rising in Malawi (Matumba et al. 2015). 28% of liver cancer cases.

Introduction

• High prevalence of mycotoxins in developing countries calls for deliberate policies that demand good understanding of its impacts pharmaceutically and economically.

• However, there is no evidence of the relationship between income distribution and aflatoxin consumption.

• Some work has been done on the pharmaceutical impacts (Matumba et al. 2014; Monyo et al. 2010).

• Little research has been conducted to examine the economic impacts especially with regard to aflatoxins that are most prevalent in an average diet.

Introduction

• The study uses nationally representative cross section data to come up with a demand system for food and assess aflatoxin consumption in diets of Malawians.

Methodology

Stage 1: Pharmaceutical analysis

• A meta-analysis on data of AF (AFB1, AFB2, AFG1 and AFG2) levels in maize, groundnuts and derived products analysed in Chitedze Mycotoxin lab.

• Obtain data using immunoaffinity column clean-up plus high performance liquid chromatography and on-line post-column photochemical derivatization-fluorescence detection.

• ANOVA was used to compare means (α=0.05).

Stage 2: Economic analysis

• Used means from Stage 1 and mapped them 1:1 on IHS3 data using agro-ecological zones.

• Translate the maize and groundnut quantities to aflatoxin consumed per capita.

• Calculated a household food budget.• Derived budget shares as a percentage of the budget.• Used median prices and fit an Almost Ideal Demand

System using quadratic Engel curves.• Calculate price, expenditure and aflatoxin elasticities

of demand.

Commodities under consideration

Maize u

fa mad

eya (

maize b

ran)

Maize g

rain (n

ot as u

fa)

Groundnut flour (N

sinjiro

)

Green m

aize

Groundnut grai

n

Maize U

fa woye

ra (Refi

ned flour)

Maize U

fa wa m

gaiw

a (Norm

al flour)

0600

12001800

Consumption per capita

Commodities

cons

umpti

on in

gra

ms

Commodities as shares of the food budget

Maize

grain (n

ot as u

fa)

Sorg

hum (mapira

)

Maize

ufa madeya

(bra

n flour)

Green m

aize

Groundnut fl

our

Groundnut

Fruits

Alcohol a

nd bevera

ges

Maize

ufa refined (fi

ne flour)

Vegetables

Other staples

Confectionarie

s and co

ndiments

Meat p

roducts

Maize

ufa mgaiw

a (norm

al flour)

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

Food as a shares of the food budget

Budg

et s

hare

s

Aflatoxin consumption in groundnuts

Kasungu

Salim

a

Lilongw

e

Mzu

zu

Blantyr

e

Karonga

Mac

hinga

Shire

Valley

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

Agricultural Development Divisions

Aflat

oxin

s in

μg p

er g

ram

Aflatoxin consumption in Maize

Kasungu

Mzuzu

Lilongwe

Blantyre

Salim

a

Machinga

Shire

valle

y

Karonga0

0.51

1.52

2.53

3.54

Afla

toxi

n qu

antiti

es in

μg

Price elasticities of demand for food

Maize g/nuts fruits meat vege alcoh condiMaize -0.965 0.099 0.002 0.241 0.305 0.048 0.039g/nuts 0.838 -1.363 -0.06 -1.765 -0.58 1.148 -0.218Fruits 0.248 -1.517 -2.32 -2.665 -1.409 -2.81 1.189Meat -0.203 0.352 0.017 -0.069 -1.616 -0.305 0.178Vege -0.138 0.439 0.031 -0.051 -0.341 -0.655 0.338alcoh -0.818 1.155 0.014 4.023 1.602 -2.649 -1.126Condi 1.102 0.041 0.247 -0.214 3.059 -14.425 -0.071

Expenditure 0.544 0.897 0.525 0.911 0.634 5.16 5.261

Aflatoxin price elasticities

Maize g/nuts

Mgaiwa -0.4825 0.0495

Woyera -0.2235 0.1275

Madeya 0.312 -0.5675

g/nuts 0.419 -0.6815

Maize 1.3795 -3.249

Households are mostly able to adjust their consumption patterns through substitution of high-priced foods, so that the effects of moderate short-term food price variations on aflatoxin consumption are relatively small.

Concluding remarks

• Results generally indicate that poor households consume higher levels of aflatoxins.

• Furthermore, simulations indicate that income changes have a lasting effect on aflatoxin consumption.

• The study therefore recommends demand side approaches to curbing aflatoxins should be used in complementing supply side interventions.

Acknowledgements

• We acknowledge funding from PACA-AU.• Expertise from Chitedze research station – Dr

Limbikani Matumba• The LUANAR team that supported the analysis.• All errors and/or omissions are the authors and

do not reflect views of PACA, LUANAR or Chitedze Research Station