An Implementation of the Stratification Index
An implementation of the stratification index proposed by Zhou (2012) <10.1177>.
The package provides two functions, srank, which returns stratum-specific
information, including population share and average percentile rank; and strat,
which returns the stratification index and its approximate standard error.
When a grouping factor is specified, strat also provides a detailed decomposition
of the overall stratification into between-group and within-group components.10.1177>