In the previous Human Development Reports, countries were divided by the quartiles of the HDI distribution into four groups of equal sizes, from “Very High” to “Low” human development groups.

This year you are using the fixed cut-off points to define the groups. Why did you introduce this this change?

There are two major reasons why we went back to fixed cut-off points between groups – first is that with the quartile grouping countries couldn’t see clearly their progress to a higher level of human development because the quartiles of the HDI distribution change values every year and second, the number of countries is always the same in each quartile group. So if a country moves up into a higher level group, another country has to move down into a lower group.

The 2014 HDI introduces a system of fixed cut-off values for the four categories of human development achievements. The cut-off values are obtained as the HDI values calculated using the quartiles of the distributions of component indicators. For more details see Technical note 1. These cut-off points (0.55, 0.7, 0.8) will be kept for at least five years and then will be revised.