PracTools: strAlloc – R documentation

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strAlloc

Allocate a sample to strata

Description

Compute the proportional, Neyman, cost-constrained, and variance-constrained allocations in a stratified simple random sample.

Usage

strAlloc(n.tot = NULL, Nh = NULL, Sh = NULL, cost = NULL, ch = NULL,
     V0 = NULL, CV0 = NULL, ybarU = NULL, alloc)

Arguments

`n.tot`	fixed total sample size
`Nh`	vector of population stratum sizes (N_h) or pop stratum proportions (W_h)
`Sh`	stratum unit standard deviations (S_h), required unless `alloc = "prop"`
`cost`	total variable cost
`ch`	vector of costs per unit in stratum h (c_h)
`V0`	fixed variance target for estimated mean
`CV0`	fixed CV target for estimated mean
`ybarU`	population mean of y (\bar{y}_U)
`alloc`	type of allocation; must be one of `"prop"`, `"neyman"`, `"totcost"`, `"totvar"`

Details

alloc="prop" computes the proportional allocation of a fixed total sample size, n.tot, to the strata. alloc="neyman" computes the allocation of a fixed total sample size, n.tot, to the strata that minimizes the variance of an estimated mean. alloc="totcost" computes the allocation of a fixed total sample size, n.tot, to the strata that minimizes the variance of an estimated mean subject to the fixed total cost. alloc="totvar" computes the allocation that minimizes total cost subject to the target coefficient of variation, CV0, or the target variance, V0, of the estimated mean.

Value

For proportional allocation, a list with values:

`alloc`	type of allocation: `"prop"`, `"neyman"`, `"totcost"`, `"totvar"`
`Nh`	vector of population sizes (N_h) or pop stratum proportions (W_h)
`nh`	vector of stratum sample sizes
`"nh/n"`	proportion of sample allocated to each stratum

For other allocations, the three components above plus:

`Sh`	stratum unit standard deviations (S_h)
`"anticipated SE of estimated mean"`	Anticipated SE of the estimated mean for the computed allocation

Author(s)

Richard Valliant, Jill A. Dever, Frauke Kreuter

References

Cochran, W.G. (1977). Sampling Techniques. John Wiley & Sons.

Valliant, R., Dever, J., Kreuter, F. (2013, chap. 3). Practical Tools for Designing and Weighting Survey Samples. Springer.

Examples

# Neyman allocation
Nh <- c(215, 65, 252, 50, 149, 144)
Sh <- c(26787207, 10645109, 6909676, 11085034, 9817762, 44553355)
strAlloc(n.tot = 100, Nh = Nh, Sh = Sh, alloc = "neyman")

# cost constrained allocation
ch <- c(1400, 200, 300, 600, 450, 1000)
strAlloc(Nh = Nh, Sh = Sh, cost = 100000, ch = ch, alloc = "totcost")

# allocation with CV target of 0.05
strAlloc(Nh = Nh, Sh = Sh, CV0 = 0.05, ch = ch, ybarU = 11664181, alloc = "totvar")

PracTools

Tools for Designing and Weighting Survey Samples

v1.2.2

GPL (>= 2)

Authors