You can graph the observations that have missing values for a particular variable. The observations with missing values are plotted and labelled by observation number (or _n). You can also plot multiple variables and their missing values which allows you to see if there are some observations that are missing more than one variable value.
To create a missing values plot in Stata, you first need to download the missingplot command from the SSC, which you do in Stata with the following command:
To generate this graph in Stata, use the following commands: