Survey Weights
Survey weights account for the design of a survey sample and other biases/errors introduced by a survey instrument.
The Basic Process
- Set survey dispositions
- Set base weights
- Apply non-response adjustments to base weights
- Calibrate the weights
See here for details about survey dispositions.
Calculating Weights
The base weight is the inverse of the probability of being sampled. Think desired over actual. As such, the sum of base weights should equal the population size.
For a SRS design, this is calculated as a simple rate. Given a population of 20,000 and a sample size of 667, the propbability of being sampled is 20,000/667 = 29.99.
For a STSRS design, the same process is applied per stratum.