Summarizing numerical variable by a categorical variable for each available year

[Budu Gulo]

I am working with three variables: return, type, and year. How can I obtain summary statistics of return by type for each available year? Put another away, I want something like
tabstat return, by( type ) for each year.

Thank you.

[Clyde Schechter]

The direct solution is:

levelsof year, local(years)
foreach y of local years {
    display `y'
    tabstat return if year == `y', by(type)
}

Another approach that gives the results in a layout with years crossed with type would be:

table year type, c(mean return)

If you want the data in memory to have these results, rather than outputing them in a table or tables

by type year, sort: egen mean_return = mean(return)

Note: In the future, please show examples of your data when asking for code. While the above solutions are fairly generic and will work with most data sets that would meet your description, the correct code often depends on details of the data that are not adequately described in words. The helpful and simple way to show example data is to use the -dataex- command. Please read Forum FAQ #12 for more information about this topic.

[Budu Gulo]

Codes work with my data. Thanks a lot Clyde Schechter! I will keep the advice in mind.

[Nick Cox]

This should also work:

egen group = group(year type), label
tabstat return, by(group)