Poverty measures

Computes the Foster-Greer-Thorbecke (FGT) family of poverty measures, plus the Sen index and the Watts index. All measures require a poverty line.

Usage

iq_poverty(
  x,
  line,
  weights = NULL,
  na.rm = FALSE,
  ci = FALSE,
  R = 1000L,
  level = 0.95
)

Arguments

x

Numeric vector of incomes (non-negative).

line

Numeric. The poverty line. Required.

weights

Optional numeric vector of survey weights.

na.rm

Logical. Remove NA values? Default FALSE.

ci

Logical. Compute bootstrap confidence intervals on the headcount, gap, severity, and Sen indices? Default FALSE.

R

Integer. Number of bootstrap replicates. Default 1000.

level

Numeric. Confidence level. Default 0.95.

Value

An S3 object of class "iq_poverty" with elements:

headcount

Numeric. FGT(0): proportion below the poverty line.

gap

Numeric. FGT(1): average normalised gap.

severity

Numeric. FGT(2): average squared normalised gap.

sen

Numeric. Sen index.

watts

Numeric. Watts index.

line

Numeric. The poverty line used.

n

Integer. Number of observations.

n_poor

Integer. Number of observations below the line.

ci

Optional list of bootstrap CIs for the four standard FGT/Sen measures (each a list with lower and upper).

level

Numeric or NULL. Confidence level.

References

Foster, J., Greer, J. and Thorbecke, E. (1984). "A Class of Decomposable Poverty Measures." Econometrica, 52(3), 761–766.

Sen, A. (1976). "Poverty: An Ordinal Approach to Measurement." Econometrica, 44(2), 219–231.

Examples

d <- iq_sample_data("income")
# Poverty line at the 20th percentile
p20 <- quantile(d$income, 0.20)
iq_poverty(d$income, line = p20)
#> 
#> ── Poverty Measures (line = 17977.94) ──────────────────────────────────────────
#> • Headcount (FGT0): 20%
#> • Poverty gap (FGT1): 0.0639
#> • Severity (FGT2): 0.029
#> • Sen index: 0.0874
#> • Watts index: 0.0891
#> • Poor: 200 of 1000 observations

# With bootstrap CIs
iq_poverty(d$income, line = p20, ci = TRUE, R = 200)
#> 
#> ── Poverty Measures (line = 17977.94) ──────────────────────────────────────────
#> • Headcount (FGT0): 20%
#> • Poverty gap (FGT1): 0.0639
#> • Severity (FGT2): 0.029
#> • Sen index: 0.0874
#> • Watts index: 0.0891
#> • Poor: 200 of 1000 observations
#> • Bootstrap 95% CIs:
#>   Headcount 95% CI: [0.181, 0.225]
#>   Gap 95% CI: [0.0552, 0.0724]
#>   Severity 95% CI: [0.0239, 0.0338]
#>   Sen 95% CI: [0.0768, 0.099]