income

Income distribution (percentages) in the Northeast US

Income distribution (percentages) in the Northeast US in 1960 and 1970 adopted from McCullagh (1980).

Usage

income

Format

year

year.

pct

percentage of population in income class per year.

income

income groups. The unit is thousands of constant (1973) US dollars.

References

McCullagh, P. (1980) Regression Models for Ordinal Data. Journal of the Royal Statistical Society. Series B (Methodological), Vol. 42, No. 2., pp. 109-142.

Aliases

• income

Examples

# NOT RUN {
print(income)

## Convenient table:
(tab <- xtabs(pct ~ year + income, income))

## small rounding error in 1970:
rowSums(tab)

## compare link functions via the log-likelihood:
links <- c("logit", "probit", "cloglog", "loglog", "cauchit")
sapply(links, function(link) {
  clm(income ~ year, data=income, weights=pct, link=link)$logLik })
## a heavy tailed (cauchy) or left skew (cloglog) latent distribution
## is fitting best.

## The data are defined as:
income.levels <- c(0, 3, 5, 7, 10, 12, 15)
income <- paste(income.levels, c(rep("-", 6), "+"),
                c(income.levels[-1], ""), sep = "")
income <-
  data.frame(year=factor(rep(c("1960", "1970"), each = 7)),
             pct = c(6.5, 8.2, 11.3, 23.5, 15.6, 12.7, 22.2,
               4.3, 6, 7.7, 13.2, 10.5, 16.3, 42.1),
             income=factor(rep(income, 2), ordered=TRUE,
               levels=income))

# }