var_tst: Variance of Stratified Pi-estimator of the Total
Description
Compute the variance of the stratified pi-estimator of the population total,
that is of the following generic form:
$$D(x_1,...,x_H) = a^2_1/x_1 + ... + a^2_H/x_H - b,$$
where \(H\) denotes total number of strata, \(x_1, ..., x_H\) are the
strata sample sizes, and \(b\), \(a_w > 0\) do not depend on
\(x_w, w = 1, ..., H\).
Usage
var_tst(x, a, b)
var_tst_si(x, N, S)
Value
Value of the variance \(D\) for a given allocation vector x.
Arguments
x
(numeric) sample allocations in strata. Strictly positive
numbers.
a
(numeric) parameters \(a_1, ..., a_H\) of variance function
\(D\). Strictly positive numbers.
b
(numeric) parameter \(b\) of variance function \(D\).
(numeric) strata standard deviations of a given study variable.
Strictly positive numbers.
Functions
var_tst_si: computes variance of stratified pi-estimator of the total
for simple random sampling without replacement design in each stratum.
Under this design, parameters of the variance function \(D\) take the
following form:
$$a_w = N_w * S_w, w = 1, ..., H,$$
and
$$b = N_1 * S_1^2 + ... + N_H * S_H^2,$$
where \(N_w, S_w, w = 1, ..., H\), are strata sizes and standard
deviations of a study variable in strata respectively.
References
Sarndal, C.-E., Swensson, B., and Wretman, J. (1992),
Model Assisted Survey Sampling,
Chapter 3.7 Stratified Sampling,
New York, NY: Springer.