deffK {PracTools}

Kish design effect

Description

Compute the Kish design effect due to having unequal weights.

Usage

deffK(w)

Arguments

w

vector of inverses of selection probabilities for a sample

Details

The Kish design effect is the ratio of the variance of an estimated mean in stratified simple random sampling without replacement (stsrswor) to the variance of the estimated mean in srswor, assuming that all stratum unit variances are equal. In that case, proportional allocation with equal weighting is optimal. deffK equals 1 + relvar(w) where relvar is relvariance of the vector of survey weights. This measure is not appropriate in samples where unequal weighting is more efficient than equal weighting.

Value

numeric design effect

Author(s)

Richard Valliant, Jill A. Dever, Frauke Kreuter

References

Kish, L. (1965). Survey Sampling. New York: John Wiley & Sons.

Kish, L. (1992). Weighting for unequal Pi. Journal of Official Statistics, 8, 183-200.

Valliant, R., Dever, J., Kreuter, F. (2018, chap. 14). Practical Tools for Designing and Weighting Survey Samples, 2nd edition. New York: Springer.

See Also

deff, deffCR, deffH, deffS

Examples

data(nhis)
w <- nhis$svywt
deffK(w)