# strAlloc: Allocate a sample to strata In PracTools: Tools for Designing and Weighting Survey Samples

 strAlloc R Documentation

## 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. (2018, chap. 3). Practical Tools for Designing and Weighting Survey Samples, 2nd edition. Springer.

nCont, nLogOdds, nProp, nPropMoe, nWilson

### 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 documentation built on Nov. 9, 2023, 9:06 a.m.