fao assessment of global undernourishment. current practice and possible improvements carlo cafiero,...

CFS Round Table on Monitoring Food Security 1

FAO assessment of global undernourishment. Current practice and possible improvementsCarlo Cafiero, ESS

Rome, 12-13 September 2011


Outline

DefinitionsCriticisms◦Appropriateness◦Usefulness◦Validity◦Precision

Conclusions and moving forward



FAO’s Undernourishment indicator

It is used as the MDG indicator 1.9Basic 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



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



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



AppropriatenessUndernourishment is defined as a continued

(chronically) insufficient caloric intakeThe 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



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



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



Validity

Two major criticisms on the validity1. 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)



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



Validity: the energy requirement thresholdThe 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)



PrecisionThough 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



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



Precision:modeling assumptionsOf 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



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 log-normal.



Conclusions and moving forward The FAO indicator is a valid measure of the share of

population having insufficient access to foodIt 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



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



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?



Thanks !


fao assessment of global undernourishment. current practice and possible improvements carlo cafiero,...

Documents

dimensions of food insecurity

chronic food deprivation

cfs round table

household level

population levelcriticisms

population rome

mdg indicator

household surveysrome