Stata Learning Module | Comparing Stata and SAS side by side

SAS represents missing values as “negative infinity” while Stata represents missing values as “positive infinity”. For example, within Stata, numbers are ordered like thisall nonmissing numbers < . < .a < .b < … < .z
In SAS the order is reversed.
Both SAS and Stata represent dates in a similar way, as the number of days before or since Jan 1 1960. So the date Jan 2 1960 is represented as a 1 in both SAS and Stata.
SAS permits you to have multiple active data files at once, while Stata only permits one active data file (in memory) at once.