Hi !

I need help with the following situation:

consider the following situation: YEAR = 1, 2 (2 LEVELS) COUNTRY = 1, 2, 3 (3 Levels) PNB = 1, 2, 3, 4 (4 levels) To be more elaborate the following program selects a random sample of size 5 without replacement from the a finite pop. of say 100 obs. The program works well. How could you modify it in a such a way that it will select a certain number of levels for YEAR, (for example 3 levels of 1's and 2 levels of 2's) and for country a certain fixed number of 2's and 3's and probably not the level 1 and so forth. This is almost selecting samples and discarding them untill you obtain the one you want. Could we have looked at each variable as strata and then select from each the required number of levels ? How one would have implemented that idea.

data econ; RETAIN K 10 N 101; DROP N K; INFILE ECONDAT; INPUT IDNUM YEAR COUNTRY PNB ; N = N - 1; IF RANUNI(0) , K/N; K=K-1; PROC PRINT;

An acceptable sample with the requirements specified above could be.

Year country PNB 1 2 3 1 2 3 1 2 4 2 1 4 2 3 1

Any help, suggestion greatly appreciated. Casimir B.