Computing Inclusion Probabilities and Sampling Weights

  1. To compute the inclusion probabilities for the first stage, from the menus choose:

    Transform > Compute Variable...

    Figure 1. Compute Variable dialog box
    Compute Variable dialog box

    Fifteen out of one hundred bank branches were selected without replacement in the first stage; thus, the probability that a given bank was selected is 15/100 = 0.15.

  2. In the Compute Variable dialog, type inclprob_s1 as the target variable.
  3. Type 0.15 as the numeric expression.
  4. Click OK.

    One hundred customers were selected from each branch in the second stage; thus, the stage 2 inclusion probability for a given customer at a given bank is 100/the number of customers at that bank.

  5. Recall the Compute Variable dialog box.
  6. Type inclprob_s2 as the target variable.
  7. Type 100/ncust as the numeric expression.
  8. Click OK.

    Now that you have the inclusion probabilities for each stage, it's easy to compute the final sampling weights.

  9. Recall the Compute Variable dialog box.
  10. Type finalweight as the target variable.
  11. Type 1/(inclprob_s1 * inclprob_s2) as the numeric expression.
  12. Click OK.

You are now ready to create the analysis plan.

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