Concentration Index versus Diversity Index
From Open Risk Manual
Concentration Index versus Diversity Index
Concentration indexes and diversity indexes are related families of metrics that aim to assess the prevalence of some category within a broader set.
Discrete versus Continuous data sets
The main different between a concentration index and a diversity index is in the nature of the statistical observations that are used as input data for the index calculation. There are two possible starting points for input data:
- The population attributes used as observations are discrete (See Categorical Variable)
- Observations are numerical (See Numerical Variable), typically continuous and summable
Examples
- Discrete: For example is the proportion of individuals in a population with total count N that belongs to Category i. A number of indexes used in diversity studies (Abundance, Richness, Margalev's, Menhinick’s diversity indexes) are based on such species counts.
- Numerical For example is a range of observations of some continuous quantity E such as risk Exposure or income. Such data will typically converted into weights