ci: A function to calculate the concentration index.

In brechtdv/rineq: Statistical Analysis of Health Inequalities

A function to calculate the concentration index.

Description

This function calculates the relative concentration index (Kakwani et al), the generalized concentration index (Clarke et al, 2002) and the concentration index with Erreygers' correction (Erreygers et al, 2009). It returns an object of class hci for which confidence intervals, summaries and plots are defined.

Usage

ci(x, y, wt = NULL, type = c("CI", "CIg", "CIc"))

concentration_index(object)

## S3 method for class 'hci'
plot(x, ...)
## S3 method for class 'hci'
print(x, ...)
## S3 method for class 'hci'
summary(object, ...)
## S3 method for class 'hci'
confint(object, parm = NULL, level = 0.95, ...)
variance_concentration_index(object)

Arguments

x	For ci, a numeric variable containing the health measure. For the print and plot methods: an object of class hci.
y	a numeric variable containing the wealth measure.
wt	a numeric variable containing the sample weights. Defaults to NULL, which is equal to a constant sample weight for all cases.
type	the type of concentration index to be calculated: relative concentration index (CI), generalized concentration index (CIg), or concentration index with Erreygers Correction CIc.
object	an object of class hci () the result of a call to RCI).
parm	always set to NULL; provided for consistency with the generic confint.
level	confidence level at which confidence intervals should be calculated. Defaults to 0.95.
...	arguments to pass on to plot, print and summary.

Details

ci returns the concentration index in an object of class hci. A number of extractor functions have been defined. The plot function returns a plot of the Lorenz curve.

Value

For ci, an object of class hci; this is a list containing the following components:

concentration_index	concentration index. The type of concentration index depends on the chosen type argument.
varC	variance of the concentration index
fractional_rank	weighted fractional rank for each case
outcome	health measure for each case
n	number of cases
call	the original call to RCI

For plot.hci, a concentration plot.

Author(s)

Saveria Willimes, Peter Konings and Niko Speybroeck

References

Clarke, P. M., Gerdtham, U. G., Johannesson, M., Bingefors, K., & Smith, L. (2002). On the measurement of relative and absolute income-related health inequality. Social Science & Medicine, 55(11), 1923-1928

Erreygers, G. (2009). Correcting the concentration index. Journal of health economics, 28(2), 504-515

Kakwani, N., Wagstaff, A., & Van Doorslaer, E. (1997). Socioeconomic inequalities in health: measurement, computation, and statistical inference.Journal of econometrics, 77(1), 87-103.

Examples

data(nigeria)
example <- with(nigeria, ci(x = wealth, y = zscore, wt = weight, type = "CIg"))
plot(example)
summary(example)

brechtdv/rineq documentation built on Feb. 21, 2024, 2:18 p.m.