Confidence limits from a standard error, a coefficient of variation or a margin of error

The comparisons of this family take an estimate and its published confidence limits. Agencies that publish a standard error, a relative standard error (coefficient of variation) or a margin of error instead give the same information; this turns it into limits at the level wanted.

Usage

limfrom(est, se = NULL, cv = NULL, moe = NULL, moelev = 0.9, conflvl = 0.95)

Arguments

est

The estimates the limits are centred on.

se, cv, moe

Give one: standard errors, coefficients of variation (relative standard errors, in percent), or margins of error.

moelev

The confidence level of the margins of error (default 0.90).

conflvl

The level of the limits returned (default 0.95).

Value

A data frame: estimate, lower, upper, se.

Details

With an estimate \(e\) and \(z = \Phi^{-1}(1 - \alpha/2)\) for the level wanted, a standard error \(s\) gives \(e \pm z s\); a coefficient of variation \(c\) (in percent) gives \(s = e c / 100\); a margin of error \(m\) at level moelev (the American Community Survey publishes 90% margins) gives \(s = m / z_{moe}\). The limits are symmetric on the estimate's scale.

See also

qltyrcd, indgap.

Examples

limfrom(c(24.1, 31.5), cv = c(8, 12))
#> ╭── Intervals from published precision ───────────────────────────────╮
#> │   Estimates  2                                                      │
#> │   Interval   normal, estimate +/- z x se (default 95%)              │
#> │                                                                     │
#> │   estimate     se  interval                                         │
#> │   --------  -----  --------------                                   │
#> │      24.10  1.928  [20.32, 27.88]                                   │
#> │      31.50  3.780  [24.09, 38.91]                                   │
#> │                                                                     │
#> │   Each interval is rebuilt from the published standard error, CV or │
#> │   margin of error, assuming a normal sampling distribution.         │
#> ╰─────────────────────────────────────────────────────────────────────╯
limfrom(1520, moe = 210)                 # a 90% margin of error
#> ╭── Intervals from published precision ───────────────────────────────╮
#> │   Estimates  1                                                      │
#> │   Interval   normal, estimate +/- z x se (default 95%)              │
#> │                                                                     │
#> │   estimate     se  interval                                         │
#> │   --------  -----  ------------                                     │
#> │      1,520  127.7  [1270, 1770]                                     │
#> │                                                                     │
#> │   Each interval is rebuilt from the published standard error, CV or │
#> │   margin of error, assuming a normal sampling distribution.         │
#> ╰─────────────────────────────────────────────────────────────────────╯