The Enterprise Guide query builder uses PROC SQL under the covers, and the LAG function is not valid in PROC SQL. You would either need to use DATA step code in a program node, or there is a custom task you can use that will calculate the lag. http://support.sas.com/documentation/onlinedoc/guide/customtasks/index.htm Under the quick links for Eguide 4.3 and later, choose the link for the Example: Calculate Lag. Download the zip file to your PC, and save the CalculateLag.dll file to 'C:\Program Files\SASHome\SASEnterpriseGuide\7.1\Custom'. When you open a new session of Eguide, under Tools - Add-in Manager, you should see the Compute Lag/Dif custom task. You may need to unblock the DLL file on your PC as well, here is more information: http://blogs.sas.com/content/sasdummy/2013/05/19/unblocking-custom-task-dlls/
... View more