FAO assessment of global
undernourishment.
Current practice and possible
improvements
Carlo Cafiero, ESS
Rome, 12-13 September 2011
CFS Round Table on Monitoring Food Security
1
Outline
Definitions
 Criticisms

◦
◦
◦
◦

Appropriateness
Usefulness
Validity
Precision
Conclusions and moving forward
Rome, 12-13 September 2011
CFS Round Table on Monitoring Food Security
2
FAO’s Undernourishment indicator
It is used as the MDG indicator 1.9
 Basic elements

◦ A distribution for habitual caloric intake is
defined for a representative individual in the
population
◦ Parameters of such a distribution are
estimated based on data from Food Balance
Sheets AND Household Surveys
Rome, 12-13 September 2011
CFS Round Table on Monitoring Food Security
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FAO’s Undernourishment indicator

Basic elements (cont’d)
◦ The probability that intake for the
representative individual falls below its
minimum level of calorie requirement
compatible with a healthy and active life is
taken as an estimate of the Prevalence of
Undernourishment (PoU) in the population
Rome, 12-13 September 2011
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Criticisms
•
•
The FAO indicator has been subject to
criticisms as a global indicator of “hunger”
Criticisms should be distinguished
depending on whether they refer to the:
– appropriateness of the underlying operational
definition of food insecurity
– usefulness for policy guidance and program
monitoring
– validity as a measure of the accepted definition of
food insecurity
– precision of the estimates produced, given the
quality of the available data
Rome, 12-13 September 2011
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Appropriateness
Undernourishment is defined as a continued
(chronically) insufficient caloric intake
 The embedded operational definition of food
insecurity is of chronic food deprivation, at the
population level
 Criticisms:

◦ Quality of the diet, as linked to an appropriate balance
of macronutrients (protein/fat/carbohydrates) and
essential micronutrients, may be equally important
◦ Temporary food insecurity may also be important and
occur even more frequently than chronic hunger
◦ Monitoring should be conducted at the individual or
household level to better target interventions
Rome, 12-13 September 2011
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Appropriateness

Criticism is valid as it points to the need for
other perspectives to be added to capture
more fully the dimensions
of food insecurity
◦ see discussion in the previous session

However, there is still great value in
assessing the extent of chronic hunger,
especially in recognition of the too limited
progress achieved so far globally
Rome, 12-13 September 2011
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Usefulness

The major criticism on the usefulness of the
indicator for policy purposes is that it
cannot be produced in a timely manner, as
the needed data are available only with a
significant delay, so that no real-time
monitoring of food crises is possible
◦ Steps are being taken to ensure that needed data
inputs are made available sooner (tomorrow’s
focus)
◦ Research is ongoing to allow forming projections
of estimated PoU based on projected economic
contingency
Rome, 12-13 September 2011
CFS Round Table on Monitoring Food Security
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Validity
Two major criticisms on the validity
1. The FAO does not make effective use of
household survey data (Smith 1999)
2. The choice of a single threshold level for
the dietary energy requirement is bound
to generate errors
(Svedberg 2000, 2002)

Rome, 12-13 September 2011
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Validity: use of surveys

Why a statistical model?
◦ Controversies exist on the possibility of
defining a minimum dietary energy
requirement at the individual level
◦ Information on habitual household food
consumption obtained from household surveys
data is affected by significant noise
Rome, 12-13 September 2011
CFS Round Table on Monitoring Food Security
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Validity:
the energy requirement threshold
The argument in Svedberg (2000) stands on existence
of a continuous joint distribution of intakes (x) and
requirements (r) in the population.
 A continuous joint distribution would assign zero
probability to the event (x = r), therefore any
population would be partitioned in two groups: the
under and the over-nourished, with no one being
considered as “adequately nourished”

◦ See Sukhatme’s criticism of Dandekar in the ’70s.

Use of the marginal distribution of intakes only,
defined as pertaining to a representative individual of
a broad group, avoids reference to a joint distribution
for intake and requirement
◦ See Naiken (2007)
Rome, 12-13 September 2011
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Precision

Though never explicitly reported, precision
of the FAO estimate at individual country
level is perforce rather limited (i.e., large
confidence intervals)
◦ Failure to report standard errors has likely
contributed to misinterpretations of the actual
value of country level estimates

Precision of the estimate depends on:
◦ Quality of the data
◦ Appropriateness of the ancillary modeling
assumptions, i.e. the assumption of Log Normal
distribution for food consumption in the
population
Rome, 12-13 September 2011
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Precision:
quality of the data

Quality of the data is a problem for both
data sources
◦ Data informing compilation of FBS
◦ Data collected through household surveys

Integration and comparison of the two
sources of data when available for the
same country and the same year promises
to improve the precision of the estimate
Rome, 12-13 September 2011
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Precision:
modeling assumptions

Of the modeling assumptions, the most
critical one is on the shape of the
distribution and on the way its parameters
are updated
◦ Due to lack of data, the distribution’s parameters
for many countries have not been updated over
many years
◦ If over time relative shares of food consumption in
the population change, not only the coefficient of
variation of food consumption may have changed,
but also the log normal model may no longer be
appropriate
Rome, 12-13 September 2011
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Precision:
modeling assumptions

Testing alternative distribution models
◦ Problem: we need a model because we do not
“trust” household level data, but we need precise
household level observations to test the model…

Ongoing research in ESS is tackling this issue
◦ Preliminary results point to the skewed-t
distribution as a promising alternative to the lognormal.
Rome, 12-13 September 2011
CFS Round Table on Monitoring Food Security
15
Conclusions and moving forward
The FAO indicator is a valid measure of the share
of population having insufficient access to food
 It should not be interpreted as a comprehensive
measure of food insecurity, but rather used in
combination with other indicators focusing on
different dimensions of food insecurity
 Its usefulness will be raised thanks to extensions
of the basic framework model in two directions:

◦ Developing projection models for undernourishment
◦ Calculating more indicators, e.g. estimates of excessive
caloric intake which is expected to be highly correlated
with nutrition related problems such as obesity
Rome, 12-13 September 2011
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Conclusions and moving forward
Its precision at individual country levels
could be greatly improved through
increased quality of the basic data, both
from Food Balance Sheets and Household
Surveys
 For that, it is imperative to improve the
collaboration with countries in collecting
better and more timely data

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Questions

Improving the data (both FBD and HS):
◦ What can be done?
◦ How can be it achieved?

Improving the model:
◦ Directions for added flexibility?
◦ Modeling/projecting over years with no
underlying data?
◦ Expansion of the scope of the analysis?
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Thanks !
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CFS Round Table on Monitoring Food Security
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