Swan's book explains:
In short answers we use me, him, etc. (informal) or I, he, etc. with a verb (more formal). The same thing happens after as and than.
Informal
- I've got the same number as him
Formal
- I've got the same number as he has.
Now, my question is, why doesn't the informal form like this:
- I've got the same number as his.
This is the reason why I think like this: My logical thinking (as a learner) prefer [... as possessive pronoun (his)] to [... as personal pronoun (him)] because it refers directly to the thing (theirs) rather than the person.
Another example:
I have the same eyes as my mother.
Or
I have the same eyes as my mother's.
In conclusion, is 'the same (thing) as (possessive pronoun)...' correct?