Here is how the Global Hunger Index (GHI) scores are calculated:
PUN | proportion of the population that is undernourished (in %) |
CWA | prevalence of wasting in children under five years old (in %) |
CST | prevalence of stunting in children under five years old (in %) |
CM | proportion of children dying before the age of five (in %) |
Standardized PUN = ^{PUN}⁄_{80} x 100
Standardized CWA = ^{CWA}⁄_{30} x 100
Standardized CST = ^{CST}⁄_{70} x 100
Standardized CM = ^{CM}⁄_{35} x 100
^{1}⁄_{3} Standardized PUN
+ ^{1}⁄_{6} Standardized CWA
+ ^{1}⁄_{6} Standardized CST
+ ^{1}⁄_{3} Standardized CM
= GHI Score
The following paragraphs describe in more detail the three-step process for calculating GHI scores.
First, values for each of the four component indicators are determined from the available data for each country. The four indicators are
Second, each of the four component indicators is given a standardized score based on thresholds set slightly above the highest country-level values observed worldwide for that indicator between 1988 and 2013.^{1} For example, the highest value for undernourishment estimated in this period is 76.5 percent, so the threshold for standardization was set a bit higher, at 80 percent.^{2} In a given year, if a country has an undernourishment prevalence of 40 percent, its standardized undernourishment score for that year is 50. In other words, that country is approximately halfway between having no undernourishment and reaching the maximum observed levels.
Third, the standardized scores are aggregated to calculate the GHI score for each country. Undernourishment and child mortality each contribute one-third of the GHI score, while the child undernutrition indicators–child wasting and child stunting–each contribute one-sixth of the score.
This calculation results in GHI scores on a 100-point scale where 0 is the best score (no hunger) and 100 the worst. In practice, neither of these extremes is reached. A value of 100 would signify that a country's undernourishment, child wasting, child stunting, and child mortality levels each exactly meet the thresholds set slightly above the highest levels observed worldwide in recent decades. A value of zero would mean that a country had no undernourished people in the population, no children younger than five who were wasted or stunted, and no children who died before their fifth birthday.
The severity scale shows the severity of hunger–from low to extremely alarming–associated with the range of possible GHI scores using the revised formula.
The thresholds for standardization are set slightly above the highest observed values in order to allow for the possibility that these values could be exceeded in the future. ↩
The threshold for undernourishment is 80, based on the observed maximum of 76.5 percent; the threshold for child wasting is 30, based on the observed maximum of 26.0 percent; the threshold for child stunting is 70, based on the observed maximum of 68.2 percent; and the threshold for child mortality is 35, based on the observed maximum of 32.6 percent. ↩