What is the result of using a DROP statement incorrectly in a DATA step?

When a DROP statement is used incorrectly in a DATA step, the result is that no variables are removed, and all remain in the dataset. This can occur if the specified variable names do not exist in the dataset or are misspelled. In such cases, SAS compiles the DATA step successfully, treating the DROP statement as if it were not present in terms of dropping variables, leading to the original dataset being retained.

The effectiveness of the DROP statement relies on the presence of the mentioned variables. If all variables listed in this statement are absent, SAS will not encounter any critical errors that would disrupt processing, nor will it raise a compilation issue. It simply ignores the non-existent variables, resulting in the final dataset containing every original variable.

This characteristic of the DROP statement underscores the importance of careful variable management within SAS programs to ensure the intended data manipulation occurs during the DATA step execution.