topic Re: Sample size change in Survey data in SAS Procedures

Sample size change in Survey data

olabuh — Thu, 05 Dec 2019 06:08:39 GMT

I am analyzing a survey data with a raw sample size of about 2.7 million, when I run the proc survey procedures, the sample size comes down to about 2 million and I am sure this is not explained by the missing data because I ran the proc freq and the missing data were very small and the sample size with the normal proc procedures was 2.7 million. Does anyone know why?

Thanks.

Re: Sample size change in Survey data

Kurt_Bremser — Thu, 05 Dec 2019 07:00:54 GMT

See if you can observe the effect with a small subset (~100 observations) of your data. If yes, post that here (in a data step with datalines, see my footnotes), and your code, so we can recreate the issue.

Re: Sample size change in Survey data

PaigeMiller — Thu, 05 Dec 2019 12:01:58 GMT

@olabuh wrote:

I am analyzing a survey data with a raw sample size of about 2.7 million, when I run the proc survey procedures, the sample size comes down to about 2 million and I am sure this is not explained by the missing data because I ran the proc freq and the missing data were very small and the sample size with the normal proc procedures was 2.7 million. Does anyone know why?

Thanks.

What specific analysis are you performing? What specific SAS PROCs are you using?

Re: Sample size change in Survey data

Watts — Thu, 05 Dec 2019 15:35:29 GMT

If you're specifying design variables (STRATA and/or CLUSTER variables), maybe some of these values are missing. Observations with missing STRATA or CLUSTER values are excluded from the analysis unless you specify the MISSING option. Also, observations with missing or negative WEIGHT values are excluded. There's more information in the survey proc documentation section Missing Values.