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Does Inflation Kill? Exposure to Food Price Inflation and Child Mortality
Daniel Kidane* and Andinet Woldemichael¥
January, 2019
Abstract
Unlike extreme malnutrition shocks, such as famine and drought which grab the attention of the media, international aid organizations and policymakers, malnutrition due to food price hikes are often neglected and their impacts on children are not well known. It is well established that malnutrition during the critical periods of early life—between inception and the first 1000 days after birth—have lasting consequences on health and mortality. In this paper, using a uniquely constructed data from Ethiopia that takes advantage of high-frequency local retail food prices, we examine the impacts of early life exposure to food price inflation on child mortality. Following survival events since inception, we estimate the causal impacts of exposure to inflation during in-utero and infancy. The results show that exposure to 10 percent inflation in staple food prices during in-utero decreases the survival of children under the age of five by about 5.4 percent. We also find that the impacts are non-linear depending on the specific month of exposure and substantially vary by observable characteristics and the type of staple food.
JEL Classification: E31, I10, I15, Q18
Keywords: Survival; Under-five; Malnutrition; Ethiopia; In-utero; Micronutrients.
_________________________
* Department of Economics, Salem State University, 352 Lafayette, St. Salem, MA 01970 USA: Email: [email protected].¥ Development Research Department, African Development Bank, Abidjan, Cote d’Ivoire: Email: [email protected].
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1. Introduction
In the wake of high and rising food prices in developing countries children are particularly a risk
of malnutrition. Unlike extreme malnutrition shocks, such as famine and drought that grab the
attention of the media, international aid organizations and policymakers, malnutrition due to food
price hikes are often neglected and their impacts on children are not well known. Households
typically respond to food price hikes by substituting expensive food items with cheaper
alternatives, probably with lower nutritional quality, resulting in micronutrient deficiencies.
Malnutrition and hidden hunger during the critical window of “early life”— in-utero and the first
1,000 days after birth—has been linked to elevated risks of impaired physical and cognitive
development that may lead to irreversible long-term impacts. The most pernicious impact of
exposure to malnutrition during early life is child mortality. Although numerous studies
document the impacts of rising food prices on children health (Brinkman et al., 2010; Christian,
2010; Woldemichael et al., 2017), the full implication on child mortality is yet to be understood.
This study fills the gap in the literature by investigating the impact of exposure to food price
inflation on child mortality in Ethiopia. We use the Demographic and Health Survey (DHS) data,
which covers more than 21,000 cases of live and deceased children who were born between 2000
and 2010. We carefully linked each child’s early life months since inception with the
corresponding monthly local staple food inflation and estimate the impacts of exposure to food
price inflation during each month since inception on under-five survival. Our data construct and
empirical approach allow us to iron out the causal impacts and possible heterogeneity arising
from the complicated biological mechanisms through which nutrition affects fetal growth,
depending on the different stages of the embryo. To the best of our knowledge, our paper is the
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first to quantify the causal impacts of exposure to food price inflation during each month of early
life on child mortality.
Biomedical literature shows that maternal undernutrition before and during pregnancy affects
fetal growth as well as alters fetal genome which dictates subsequent growth trajectories in
what is referred to as “fetal programing” (Barker and Clark, 1997; Wu et al. 2004). Fetal
nutrition status is determined by the mother’s dietary intake and nutrient stores, nutrient
delivery to the placenta, and placental transfer capabilities (Barker and Clark, 1997; Owens et
al, 1989).1 Moreover, intrauterine environment in general and fetal nutrition and oxygen in
particular change the concentration of growth-influencing fetal and placental hormones such as
insulin and insulin-like growth factors (IGFs) which play key role in fetal growth. Therefore,
fetal growth is especially vulnerable to maternal dietary deficiencies, such as protein and
micronutrients, during the pre-implantation and during the period of rapid placental
development (Wu et al., 2004). Regardless, fetal malnutrition results in various complications
even after birth resulting in, for instance, preterm birth, low birth weight and predisposing the
child to certain diseases and ultimately death.
It is also well established that the impacts of maternal malnutrition during pregnancy vary
depending on the specific stages of fetal growth. Maternal undernutrition around conception
time influences the growth trajectory of the fetus as it affects the sensitivity of early embryonic
growth to nutrients. Whereas undernutrition in the last trimester affects fetal development,
resulting in fetal wasting and consumption of fetal amino acids by the placenta putting a
downward pressure on fetal growth trajectory during early gestation period and altering the
subsequent need for nutrition in late gestation (Leese, 1990 in Barker and Clark, 1997).
1 Some of these factors, such as maternal nutrient stores and anemia level, are determined well before conception.
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One of the innovations in our paper is that our empirical model explicitly accounts for non-
linearity of the impacts arising from the biological mechanism through which malnutrition
affects fetal growth and ultimately mortality. Moreover, our approach explicitly accounts for
the cumulative effects of malnutrition experienced throughout early life periods since inception
and control for it to net out the causal impacts of exposure to food price inflation during each
month of early life.
A number of empirical studies show that shocks experienced during in-utero and early childhood
have lasting consequences on many later-life outcomes, such as health, education and skills
formation, labor market outcomes, and social behavior (Godfrey and Barker, 2000; Behrman and
Rosenzweig, 2004; Cunha and Heckman, 2007; Case and Paxson, 2008; Hoddinott et al., 2008;
Currie, 2009; Case and Paxson, 2010; Currie and Almond, 2011; Hoddinott et al., 2013). In
times of high food price inflation, the resulting loss in purchasing power adversely affects
welfare through several channels including lower consumption levels, lower investments in
education and worse health and nutrition outcomes. Children are particularly at risk during high
food price inflation as reduction in real income forces households to not only reduce their
spending on food but also to switch from relatively more expensive sources of protein such as
meat, fish and eggs to cheaper cereals with inferior nutritional values (Akinlo and Odusanya,
2016). The resulting nutritional deficiencies due to poor dietary quantity and quality leads to
malnutrition, concomitant increases in infectious diseases and thereby mortality. Moreover, prior
studies (Wodon and Zaman, 2008; Brinkman et al, 2010; Christian, 2010) indicate that declines
in nutritional status as a result of a surge in food prices may cause poor birth outcomes, like fetal
growth restriction and preterm birth, which are also associated with infant and child mortality.
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There is a dearth of evidence examining the association between exposure to high food prices
and child mortality. In the context of developing countries, the consensus is that economic
downturns and exposure to high food prices adversely affect the survival of children (Baird et al.,
2011; Friedman and Schady, 2009; Lee et al., 2013). Baird et al. (2011) and Friedman and
Schady (2009) also noted that mortality of infant girls is significantly sensitive to such shocks
than that of boys. A number of nutritional pathways have been illustrated in the literature in that
economic crisis and hikes in food prices may increase infant and child mortality. A decrease in
food availability due to such crisis can lead to a reduction in dietary quality (Fledderjohann et al.,
2016; Darnton-Hill and Cogill, 2010) which increases childhood wasting and stunting,
intrauterine growth restriction, and micronutrient deficiencies (Christian, 2010) that leads to
higher prevalence of morbid diseases and mortality.2
Our paper contributes to the existing literature in a couple of dimensions. First, unlike prior
studies, which rely mostly on annual mortality rates, we use a unique dataset with high frequency
local market prices to estimate the effects of exposure to food price inflation on child survival.
Second, we show that survival does not only depend on what happens to children after birth but
also in-utero circumstances. To our knowledge this issue has not been documented and this study
will attempt to answer this very important question.
Our focus on Ethiopia is motivated by two important factors. First, it experienced historically
higher levels of food price inflation for sustained period of time between 2005 and 2010.
2 High food prices may also reduce mortality rates of infants and children. During times of high food prices, the real income of the household could be depressed. Baird et al. (2011) pointed out that this reduces the opportunity cost of parental time such as taking children for health visits, breastfeeding, cooking and collecting clean water which may improve child health outcomes. In fact, Miller and Urdinola (2010) find that exogenous declines in the price of coffee in Colombia was associated with lower infant mortality due to the fact that the relative price of health decreases as the value of time declines with falling prices of coffee.
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Although the country had mild inflationary episodes in the past, the food price inflation
experienced in 2008—2009 were unprecedented and among the highest in Africa.3 The extent to
which this sustained price surge impacted childhood mortality is not well documented. Second,
the country is one of the countries with high under-five child mortality in the world.4 In this
regard, it is imperative to understand and quantify how malnutrition and hidden hunger due to
food price hikes exacerbate the prevailing high under-five child mortality rate.
The findings in this study show that exposure to 1 percent inflation in staple food prices during
in-utero and the first 6 months after birth decrease childhood survival by about 5.4 percent and
8.6 percent, respectively. We also find that the impacts are non-linear, depending on the specific
month of exposure and substantially vary by observable characteristics and the type of staple
food.
The remainder of the paper is organized as follows: Section 2 presents the data. Section 3
outlines the empirical strategy and Section 4 discusses the findings of the study. Finally, Section
5 concludes the paper.
3 Studies suggest that expansionary monetary policy, higher domestic demand, structural reforms and the rising international prices of food and oil as key driving factors behind the high level of inflation (Alem and Söderbom, 2012). At the peak of the global food crisis, in July 2008, annual food price inflation in Ethiopia surpassed 90% (Durevall et al., 2013). Between 2007 and 2008, food price inflation, which accounts for more than 50% of the CPI consumption basket, rose from 18.2 percent to 91.7 percent (CSA, 2009). The level of inflation during this period was even higher for major staple crops; teff, wheat, maize, barley, sorghum and enset which account for more than 50 percent of the total daily calorie intake among Ethiopian households. For instance, between 2008 and 2009, the month-on-month inflation levels of some of these staple particularly that of maize and teff, were well above 100% (see Figure A1 in Appendix A).
4 The level of child mortality rate still high compared to the global average. In 2011, according to a report by Central Statistical Agency of Ethiopia (CSA, 2012), infant mortality rate was 59 deaths per 1000 live births, while an estimated 88 children in every 1,000 live births died before the age of five. This indicates that a total of 67% of all deaths of under-five children in Ethiopia take place before a child’s first birthday, which was one of the highest in the world. The high infant and under-five mortality rates in Ethiopia are primarily due to a wide range of diseases, such as acute respiratory infection, diarrhea, prematurity and newborn infection that children suffer at their early life, could be attributed to exposure to malnutrition due to high food price inflation during the critical periods of their early-life growth. A recent study by Woldemichael et al. (2017) indicated that exposure to food price inflation while in-utero and during infancy has detrimental and long-term impacts on malnutrition and the incidence of stunting and wasting among Ethiopian children which is strongly associated with high child mortality.
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2. The Data
This study uses the Ethiopian Demographic and Health Survey (EDHS) data collected in two
rounds in 2005 and 2010. The EDHS survey collects detailed information on children’s vital
statistics such as date of birth, date of death, if deceased. Women were also asked if they were
pregnant at the time of survey or ever had a pregnancy that was miscarried, aborted or ended in a
stillbirth. We use this information to construct retrospective birth and death histories since
inception. The survey also has comprehensive information on parental and household
characteristics. The two waves cover about 21,366 live and dead children under the age of five
and 10,987 cases of live and terminated pregnancies. Moreover, the survey covers all regions in
the country, making it one of the few nationally representative and detailed household surveys on
children’s health.
Panels (a) and (b) in Table (1) show the proportion of children under the age of five according to
their survival status since inception and since birth, respectively. As shown in panel (a), under-
five mortality has declined slightly from 7.4% in 2005 to 7.2% in 2010, underscoring some
improvement in reducing child mortality. In panel (b) that includes all events since inception,
while the proportion of live pregnancy cases declined slightly from 23.5 % in 2005 to 21.7 % in
2010, terminated pregnancies have spiked from about 9% in 2005 to 14% in 2010. Such high
increase in pregnancy termination could be attributed to a host of factors including severe
malnutrition. Moreover, increased access to family planning services, including abortion clinics
could be part of the story, which is beyond the scope this paper.
Table 1: Survival Events
2005 2010 Pooled(a): Events since birth
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Child alive (%) 92.60 92.80 92.70Child dead (%) 7.38 7.20 7.28No. of obs. 9,719 11,647 21,366
(b): Events since inceptionPregnancy unborn: alive (%) 23.50 21.70 22.50Pregnancy terminated (%) 8.84 13.60 11.50Child alive (%) 62.60 60.10 61.20Child dead (%) 4.99 4.67 4.81No. of obs. 14,371 17,982 32,353
Source: Authors’ computations
One of the key challenges in the quality of the DHS data is recall bias. Survey respondents in
countries like Ethiopia where there is low level of literacy and numeracy with limited practice of
keeping vital records, they are less likely to accurately remember distant births and deaths. This
may lead to a recall bias and potentially underestimate or overestimate the impact depending on
the direction of the bias. Recall bias is also an important source of measurement error in both the
dependent variable and the corresponding levels of inflation that a child is exposed to. In
addition to the bias on the direction and magnitude of the coefficients, measurement error due to
recall bias could inflate standard errors and hence make the coefficients statistically
insignificance. However, we do not believe this to significantly affect our results as our focus is
on relatively recent periods where we consider children who were in-utero, died while in-utero,
born alive or died after they were born in the last five years between 2001 and 2010.
Another data quality problem that can potentially lead to underestimation of mortality rates is if
mothers selectively omit to report non-surviving cases, such as miscarriages, stillborn, and
neonatal death. However, according to the EDHS, misreporting of such deaths are less severe
and are found to be within the normal range for deaths occurring during 0—4 years preceding the
survey (CSA and ORC Macro, 2006; CSA and IFC-Int, 2012). This to some extent validates our
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focus to use recent birth history which is less likely to be contaminated by recall bias and
selective omission.
For food price information, we use monthly retail food prices data collected by the Ethiopian
Central Statistical Agency (CSA) between July 2001 and December 2010. The monthly price
survey collects data on prices of thousands of goods and services from 119 representative urban
markets and the CSA uses these data to analyze prices and construct monthly Consumer Price
Index (CPI) at the national and regional levels. We have information on inflation for every
under-five birth history covered in the 2010 survey and majority of the cases covered in the 2005
survey. For older children covered in the 2005 survey, we do not have the corresponding price
data prior to July 2001 as shown in Figure 1 below. Hence, we drop observations out of our
analysis.
Figure 1: Kernel distribution of inception months by survey year Source: Authors’ computations
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We then spatially linked the DHS clusters with the high-frequency local market prices, using a
GIS-based, Nearest Neighbor Matching algorithm (see Figure 2). We use the reported date of
birth information in the DHS survey for each live birth, and duration of pregnancy at the time of
survey for live unborn cases and month of termination for terminated cases. We then use month
of inception as an anchor to match each live and dead case (fetus, infant, child) month of “early
life” with the corresponding monthly inflation rates. We do this all the way from inception to the
first 15 months after birth. Such an approach allows us to identify the exact month of “early life”
during which exposure to inflation has the most impact on mortality.
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Figure 2: Spatial Nearest Neighbor Match between Local Market Hubs and DHS Clusters
Note: The Red dots correspond to market centers; the Green dots correspond to the 2010 DHS cluster areas, the Yellow dots corresponds to the 2005 DHS cluster areas, the outer shaded buffer corresponds to 50 km radius, and inner shaded buffer circles indicates the 25 km radius from the market centers.
For our analysis, we use a composite price which is constructed by calculating the weighted
average price of six major staple foods which are commonly consumed among Ethiopian
households--Teff, Wheat, Maize, Barely, Sorghum, and Enset.5 The weights are calculated based
on each staple’s share out of total calorie consumed in the household. The weights are obtained
from the Ethiopian Household, Income and Consumption (HICE) surveys conducted in 2000 and
2005. As shown in Table (2) there is a substantial variation in terms of both calorie and
expenditure shares of each staple across regions. For instance, in Addis Ababa Teff constitutes
about one fourth of the total calorie intake, whereas Maize is the dominant source of calorie in
Gambella region. There are slight changes in consumption expenditure share of the staples
5 These staples provide important micronutrients and carbohydrate that are essential for the mother, the fetus, and the growth of the infant. For instance, teff, a gluten-free grain is a good source of essential minerals (iron, magnesium, and calcium), carbohydrate/fiber, vitamin B-12, protein (Baye, 2014).
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between the two survey periods. Given the fact that consumption patterns have changed slightly
between the two survey periods, we also constructed two separate calorie weights for the period
before and after 2005. This makes the level of food price inflation spatially comparable.
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Table 2: Share in Total Expenditure and Total Calorie (2005)
Region
Teff Maize Wheat Barley Sorghum Enset Total Staples
Exp Cal Exp Cal Exp Cal Exp Cal Exp Cal Exp Cal Exp Cal
Tigray 8.7% 7.0% 7.1% 1.9%
8.1
%
8.7
%
2.3
%
3.0
% 6.8% 8.9% 0.0% 0.0%
33.0
%
29.5
%
Affar 7.9% 8.0% 7.7% 5.5%
2.1
%
7.3
%
0.2
%
0.1
% 6.4% 1.0% 0.0% 0.0%
24.2
%
21.9
%
Amhara
11.4
% 8.7% 3.9% 5.0%
6.2
%
7.5
%
3.1
%
4.4
% 5.0% 5.8% 0.0% 0.0%
29.6
%
31.4
%
Oromiya 6.0% 4.7%
11.0
% 7.5%
4.9
%
6.0
%
1.9
%
2.8
% 4.6% 4.1% 2.5% 5.3%
30.9
%
30.4
%
Somalie 0.8% 0.8% 9.8% 7.0%
8.2
%
6.9
%
0.4
%
0.1
% 4.6% 7.1% 0.0% 0.0%
23.8
%
21.9
%
Bemshang
ul 2.8% 4.9% 4.8% 6.0%
0.4
%
0.5
%
0.1
%
0.0
%
18.3
%
11.7
% 0.0% 0.0%
26.4
%
23.1
%
SNNPR 1.1% 1.7% 7.6%
11.2
%
1.6
%
2.4
%
0.7
%
0.5
% 1.3% 1.9%
18.2
%
14.5
%
30.7
%
32.2
%
Gambela 1.7% 6.6%
16.6
%
46.0
%
1.2
%
3.2
%
0.0
%
0.1
% 4.3%
12.5
% 1.0% 3.2%
24.8
%
71.4
%
Harari 4.8% 9.8% 3.2% 1.5%
3.7
%
5.0
%
0.1
%
0.3
%
10.3
% 7.5% 0.0% 0.0%
22.0
%
24.1
%
Addis 13.3 23.7 0.5% 1.3% 1.6 4.0 0.1 0.4 0.1% 0.0% 0.2% 0.0% 15.7 29.5
13
Ababa % % % % % % % %
Dire Dawa 5.7% 6.8% 3.7% 0.4%
2.7
%
4.3
%
0.1
%
0.3
% 8.3% 5.9% 0.0% 0.0%
20.6
%
27.1
%
Average 5.8% 7.5% 6.9% 8.5%
3.7
%
5.1
%
0.8
%
1.1
% 6.4% 6.0% 2.0% 2.1%
25.6
%
31.1
%
Source: Authors’ computations using the Household, Income and Consumption (HICE) surveys conducted in Ethiopia in 2005.
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As shown in Figure (3) and Table (3), there are considerable differences in the level of inflation
that children were exposed to while they were in-utero and during infancy. Deceased children
were exposed to a higher level of food price inflation compared to those who were alive,
regardless of when they were exposed to the inflation. For instance, for those children who were
born before 2005, the average food price inflation (the composite price inflation) sustained by
dead children during in-utero and during infancy were, respectively, 3.4 and 7.8 percentage
points higher than that of alive children. This shows the importance of investigating the link
between exposure to food price inflation and child mortality.
0.2.4.6.81
Pro
porti
on
-100 -50 0 50 100Inflation (%)
Dead Alive
In-Utero
0.2.4.6.81
Pro
porti
on
-100 -50 0 50 100 150Inflation (%)
Dead Alive
During Infancy
Figure 3: Exposure to Food Price Inflation and Survival Status
Source: Authors’ computations.
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Table 3: Average Food Price Inflation (%) by Survival Status
Whole Sample Inception: Before 2005 Inception: 2005-2010
Aliv
e Dead
Poole
d Alive Dead
Poole
d
Aliv
e Dead
Poole
d
Exposure during In-Utero
Teff
18.6
5
21.2
8 18.76 13.35 14.79 13.42
21.2
0
25.2
2 21.35
Wheat
16.9
4
21.4
5 17.12 15.01 20.15 15.25
17.8
7
22.2
4 18.03
Maize
17.9
6
25.2
3 18.25 23.92 32.26 24.30
15.1
0
20.9
7 15.32
Barley
17.2
7
21.0
4 17.43 15.37 18.40 15.51
18.1
9
22.6
4 18.35
Sorghum
16.9
2
21.7
5 17.11 17.68 24.21 17.99
16.5
5
20.2
6 16.68
Enset
14.8
1
17.5
9 14.92 1.523 4.658 1.669
21.1
8
25.4
1 21.34
Staple (Composite)
16.7
5
20.5
0 16.90 13.71 16.97 13.86
18.2
1
22.6
4 18.37
No. of obs.
16,55
7 5,429
11,12
8
Exposure during Infancy (0-6)
Teff
13.2
9
19.7
9 13.55 10.86 14.58 11.03
14.4
5
22.9
5 14.77
Wheat
14.7
0
19.0
1 14.87 10.13 14.03 10.32
16.8
8
22.0
2 17.08
Maize
14.2
7
23.7
3 14.65 16.56 19.30 16.69
13.1
8
26.4
2 13.67
Barley
14.0
5
20.1
4 14.30 9.545 13.82 9.743
16.2
2
23.9
7 16.51
Sorghum 12.9 20.1 13.23 12.96 16.81 13.14 12.9 22.1 13.27
16
4 0 3 0
Enset
8.90
0
14.1
4 9.111
-
2.714 -0.964 -2.633
14.4
8
23.2
7 14.80
Staple (Composite)
12.3
6
19.5
7 12.65 8.239 13.09 8.465
14.3
4
23.5
0 14.68
No. of obs.
15,76
0 5,145
10,61
5
Source: Authors’ computationsNote: Composite price of the six staple crops is weighted average using calorie shares as weights.
Control variables
In our formal econometric analysis in the next section we control for a number factors. Table (4)
provides a descriptive summary of control variables including household, parental and
geographic characteristics. Household characteristics include household size, household head’s
gender and age, the number of under-five children in the household, wealth quartiles and
religion. Maternal variables included in the model are marital status, age, height, years of
education, age at first birth, age at first cohabitation, body-mass-index (BMI), adjusted
hemoglobin, and dummy variable indicating whether the mother was anemic or not. In order to
capture intra-household allocation of resources and the bargaining power of mothers within the
household, we also control for the husband’s age, education and occupation.
In addition to individual and household-level characteristics, we control for geographic factors
such as the location of residence, altitude, “geodesic” distance to the market hub, travel time (in
minutes) to the nearest town/city of 50,000 or more inhabitants. Furthermore, we control for
population density of the cluster and the number of drought episodes between 1981 and 2000. It
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also captures factors that affect both food price inflation and child mortality including nutritional
interventions by government and non-governmental organizations in response to malnutrition
shocks.
Table 4: Descriptive Summary of Control Variables Dead Alive Pooled Dead Alive Pooled(i) Household (iii) HusbandHousehold Size 5.32 6.16 6.10 Age 37.18 37.41 37.39
(2.41) (2.31) (2.33) (11.69) (10.95) (11.01)HH: Male 83.0% 83.7% 83.6% Years of Education 0.56 0.68 0.67HH: Age 37.66 37.91 37.89 (0.99) (1.08) (1.07)
(12.13) (11.80) (11.83) Occ. Farming 79.4% 74.6% 74.9%No. of U5 Children 1.09 1.84 1.78
(0.95) (0.81) (0.84) (iv) GeographicWealth Qnt: 1st 31.2% 28.5% 28.7% Urban 12.1% 15.9% 15.6%Wealth Qnt: 2nd 30.3% 26.6% 26.8% Altitude 1,722 1,722Wealth Qnt: 3rd 24.3% 25.2% 25.2% (676) (676)Wealth Qnt: 4th 14.2% 19.7% 19.3% Distance (Km) 35.33 33.75 33.86Orthodox Christian 33.9% 34.9% 34.9% (28.64) (28.98) 28.95Muslim 44.6% 43.2% 43.3% Travel time (min.) 422.20 402.68 404.11
(327.05) (339.85) (338.96)
(ii) Maternal Malaria 0.08 0.07 0.07
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Married 89.2% 89.6% 89.5% (0.04) (0.04) (0.04)Age 28.84 29.03 29.02 Population density 274 671 642
(7.37) (6.72) (6.77) (2,645) (3,980) (3,890)Height (cm) 156.56 157.45 157.38 Drought episodes 6.52 6.53 6.53
(6.59) (6.58) (6.58) (2.51) (2.52) (2.52)Years of Education 0.95 1.41 1.37
(2.32) (3.00) (2.96)Age at first birth 18.64 18.81 18.80
(3.68) (3.66) (3.66)Age at first cohabitation 16.10 16.51 16.48
(3.58) (3.63) (3.63)BMI 21.53 21.92 21.89
(10.26) 11.61 11.51Adjusted hemoglobin 123.63 126.72 126.49
(21.11) (19.36) (19.52)Anemic 24.4% 19.5% 19.8%No. of obs. 1,556 19,810 21,366 1,556 19,810 21,366
Source: Authors’ computations
3. Empirical Model
Our focus is on estimating the impact of exposure to food price inflation both during in-utero and
during the first 6 months after birth on infant and child survival rates. We use simple Cox
proportional hazard model to estimate the effects of exposure to food price inflation on the
survival probabilities of infants and children. The Cox proportional hazard model is one of the
most commonly used survival model because of its flexibility and no distributional assumptions
on the baseline hazard function (Cox, 1972). In our baseline specification, we estimate the
effects of exposure to average food price inflation during in-utero on survival. In the baseline
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model, the distribution of hazard of child i at age a conditional on observed characteristics can
be written as
H i (a∨X i )=h ( a∨0 ) . exp (γ π i ,(¿−utero)+β X i ) , (1 )
where h (a∨0 ) is the baseline hazard rate (mortality rate)6 at age airrespective of exposure to
food price inflation or other factors, π i ,(¿−utero)is the average food price inflation that child i was
exposed to during in-utero, γis the coefficient of interest measuring the impact of exposure to
food price inflation while in-utero, X i is a vector of control variables including child, parental,
household, geographic, and temporal characteristics as well as survey year dummies which
potentially affect children’s survival, and β is the corresponding vector of coefficients to be
estimated.
Child-level factors include birth order and month of birth. Parental characteristics include
variables that capture demographic and socioeconomic factors, which enter the child health
production directly and indirectly, including mother’s age, marital status, years of education,
occupation, age at first birth and age at first cohabitation (or marriage), and religion. In addition,
we control for husband’s age, years of education and occupation. The vector also includes
parental health factors that could predispose a child to certain life-threatening diseases or death.
In order to control for such factors, the regression includes mother’s height, hemoglobin level,
BMI, and whether she is anemic or not. Household-level factors include age of household head,
household size, the number of under-five children in the household, religion, wealth index, etc.
Geographic characteristics include location of residence, altitude, dummies for regional states,
dummies for survey year, and interaction terms of survey year and regions. Moreover, given the
6 The baseline hazard rates are unknown but could be retrieved after estimation of the full model.
20
fact that there is considerable variation in the availability of nutrition depending on crop
plantation and harvest seasons, we control for month of birth.
It is also important to note that in the context of rural Ethiopia, the impacts of food price inflation
could vary by households' status as net-sellers or net-buyers. Net-selling households could
benefit from the rise in price of the crop that they produce and sell at the market and hence
increase in their crop income. On the contrary, for a constant level of income, net-buyers could
suffer from such hikes in food prices as they will be forced to reduce the quantity and quality of
food (calorie) they purchase. The effects of food price inflation on calorie intake could,
therefore, vary by households’ net-seller and net buyer status. One of the disadvantage in our
data is that we do not have information on which household is net-buyer or net-seller. We
attempt to address this issue in two different ways. First, instead of including inflation of each
staple crop separately in our model, we use a composite staple food price inflation consisting of
five staple crops using their calorie weights for each region. In this case, even if a household is
net-seller of one crop it could be net-buyer of the other which minimizes the potential bias.
Second, we include location of residence (urban versus rural) dummy in our regressions as a
proxy for net-buyer/net-seller status, albeit a strong assumption.
Non-linearity, heterogeneous exposure time and cumulative effects
Another important issue is non-linear effects depending on exposure during the specific stage of
fetal growth. For instance, exposure to malnutrition during the first trimester could have different
impact on survival as compared to exposure to the same level of food price inflation in the third
trimester during which fetal growth is accelerated. We address this issue by running the model
for each month of exposure. Specifically, we estimate the following model
21
H i (a∨X i )=h ( a∨0 ) . exp ( γk π i ,(k)+β X i) ,∀ k∈ [−9 ,⋯ , Birth ,⋯ ,+6 ] , (2 )
where k is month of exposure and γkcaptures the effects of exposure to food price inflation during
the k thmonth. However, one of the shortcomings of Equation (2) is that it does not account for
the cumulative impacts of exposure during months prior to monthk . As such, the coefficient γk
could be picking up not only the effects of exposure to food price inflation during thek thmonth
but also the effects from all k−1months. In order to account for this, we include the cumulative
average food price inflation of the previous J=k−1 months in the regression. We calculate the
cumulative average food price inflation asΠ i , J<m<a= ∑j=inception
J ( π ij
J ), where Π i , J<m<ais the
cumulative average inflation of the previous Jmonths. Then the model that accounts for
heterogeneous exposure time and cumulative effects is given by
H i (a∨X i )=h ( a∨0 ) . exp ( γk π i ,(k)+γ J Π i ,J <m<a+β X i) ,∀ J , m∈[−9 , …, Birth ,…,+6] , (3 )
where γJ is a coefficient on the cumulative average staple food price inflation for months prior.
4. Results and Discussion
Table (5) presents the results from the Cox proportional hazard estimates. Specification (1)
shows the coefficients without including controls. Specifications (2) - (6) incrementally add
vectors of controls. As shown in Panel (a) in Specification (1), the exposure to food price
inflation during in-utero reduces under-five survival rate by about 0.002 percentage points,
which is statistically significant at 5% confidence level. When we control for household and
parental characteristics, the coefficient doubles and become statistically significant at 1%.
Controlling for geographic characteristics, survey year and region-year interaction dummies,
further increases the magnitude of the coefficient to 0.005. This implies that exposure to 10%
22
higher level of month-on-month staple food price inflation during in-utero decreases under-five
survival rate by 5.4%. For children who were in-utero during period of high food price inflation,
this is a large magnitude to be concerned of.
Table 5: Cox Proportional Hazard Estimates: The Impact of Exposure to Staple Food Price Inflation (1) (2) (3) (4) (5) (6)
Panel (a)In-utero -0.002** -0.003*** -0.004*** -0.005*** -0.005*** -0.005***
(0.001) (0.001) (0.001) (0.001) (0.001) (0.001)
Observations 16,667 16,667 16,567 16,567 16,567 16,567
Panel (b)Infancy 0.001 0.001 0.000 -0.007*** -0.007*** -0.008***
(0.002) (0.002) (0.002) (0.002) (0.002) (0.002)
Observations 18,418 18,418 18,308 18,308 18,308 18,308Household Char. -- X X X X X
Parental Char. -- -- X X X XGeographic -- -- -- X X XSurvey Year -- -- -- -- X X
23
Interaction Terms -- -- -- -- -- XRobust standard errors in parentheses. *** p<0.01, ** p<0.05, * p<0.1
Panel (b) shows the estimated coefficients on the impacts of exposure to staple food price
inflation during the first six months after birth. The coefficients in specifications (1) - (3) are
positive but statistically insignificant. However, when we control for geographic characteristics,
survey year, and region specific time-varying shocks, the coefficients become negative and
significant at 1%. The results show that exposure to 1% higher staple food price inflation during
the first 6 months after birth, reduces under-five survival by 0.008 probability points.
Table (6) shows the results for restricted sample of cases. Columns (1) - (2) show the estimates
for cases located within 50 and 25 km radius from the centroid. The coefficients on the in-utero
exposure are -0.005 and -0.006, respectively, for the subsamples within 50 and 25 km radius.
Similarly, coefficients on infancy exposure to inflation are negative and statistically significant.
Table 6: Cox Proportional Hazard Estimates: The Impacts of Exposure to Staple Food Price Inflation by Distance from Market and Survey Year
(1) (2) (3) (4)50 Km Radius
25 km Radius
2010 Survey
2005 Survey
Panel (a)In-utero -0.005*** -0.006*** -0.005*** -0.007**
(0.002) (0.002) (0.002) (0.003)
Observations 13,005 7,378 11,303 5,264
Panel (b)Infancy -0.008*** -0.009*** -0.010*** -0.006
(0.002) (0.003) (0.002) (0.004)
Observations 14,527 8,242 11,047 7,261Robust standard errors in parentheses. *** p<0.01, ** p<0.05, * p<0.1
24
In order to address non-linearity and heterogeneity in the impacts, we estimate the model in
equation (1) for each month of exposure since inception and the results are shown in Figure (4).
While the coefficients and the 95% confidence interval are shown on the y-axis, month of
exposure are shown in the x-axis. Exposure to staple food price inflation during different in-
utero months decreases survival significantly. Although there are some non-linearity in the
impacts, exposure to 1% higher level of food price inflation during any one of in-utero month
decreases child survival by up to 0.01 percentage points. However, the effects of exposure after
birth decrease and become insignificant, especially after the 6th month.
Figure (5) shows the results after accounting for the cumulative average inflation during prior
months. For comparison, the figure also shows the baseline estimates without accounting for the
cumulative effects. Interestingly, after we control for the history of price shocks, the magnitude
of the impacts increased for any given month of exposure. -.02
-.01
0.01
.02
beta
coe
ffici
ent
- -2 -4 -6 -8 Birth +2 +4 +6 +8 +10 +12Month of exposure
Figure 4: Impacts of Exposure to Staple Food Price Inflation during Each Month of Early Life
25
-.01
-.005
0.005
beta
coe
ffici
ent
- -2 -4 -6 -8 Birth +2 +4 +6 +8 +10 +12Month of exposure
Baseline Estimates Controlling for cumulative effects
Figure 5: Impacts of Exposure to Staple Food Price Inflation during Each Month of Early Life Controlling for The Cumulative Effects
We also find considerable level of heterogeneity in the impacts depending on the type of staple
food. Figure (6) show the estimates for each of the six cereals that are staples in different parts of
the country—teff, wheat, maize, barley, sorghum, and enset. The results show that in-utero
exposure to teff price inflation has the highest impact on child survival followed by maize. For
instance, the impacts of exposure to 1% higher level of teff price inflation on child survival range
from -0.005 to -0.012 probability points. Children who were exposed to 1% higher level of teff
price inflation during the 8--9th months of pregnancy have a 0.012 probability point lower chance
of survival.
26
-.015
-.01
-.005
0.005
beta
coe
ffici
ent
- -2 -4 -6 -8 Birth +2 +4 +6 +8 +10 +12Month of exposure
Teff WheatMaize BarleySorghum Enset
The effects of Food Price Inflation on Infant and Child Survival
Figure 6: Impacts of Exposure to Staple Food Price Inflation during Each Month of Early Life Controlling for the Cumulative Effects
6. Conclusion
The medium- and long-term consequences of malnutrition during early life on children’s health
are well understood, with the impacts having potentially determining future health, educational
achievement, job market, family formation, social behavior, and many other life-course
outcomes during adulthood. But there is limited knowledge on the causal impacts of hidden
hunger and malnutrition of pregnant women and children on mortality. This paper investigates
the impacts of exposure to malnutrition and hidden hunger, due to food price inflation, during
the critical periods of early life on child mortality. We use data from the Ethiopian
27
Demographic and Health Survey and high frequency local retail food price data, matching each
child’s months of early life since conception with the corresponding levels of inflation. We
carefully linked the two datasets using a GIS-based Nearest Neighbor Matching algorithm. Our
focus is on children aged 6–59 months and six major staple foods in Ethiopia.
We find that exposure to high food price inflation during the critical window of early life
significantly increase under-five mortality. Owing to the complicated biological mechanisms
that govern the link between nutrition and human growth, the impacts are non-linear and vary
by the specific month of exposure. The results are heterogeneous over some observables and
the type of cereals but robust to different empirical specifications.
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Additional Tables and Figures
Figure A1: Staple Food Price Inflation: 2001-2011
33