On the page with the list of merit sources, opposite each name is the number of merits they receive for distribution. Or is this information not displayed for regular users?
Yes, it's not visible for the regular members of the forum may be you are seeing those stats because of you are a Staff Member. Normal users don't even know the names of all merit sources.
So far I have known the name of the merit source member only by looking at the ratio of sendable merit and earned merit using BPIP Extension.
Certain users are designated as "merit sources". They can create new merit out of nothing, up to a limited number per month (which differs per source). I will not be posting a definitive list of merit sources (so that people don't bug them too much), though you'll soon figure out who they are if you pay attention.