Consider the following sentences:
- I miss you more than him.
- I miss you more than he.
What do you notice?
"I miss you more than him." is another way of saying "I miss you more than I miss him."
"I miss you more than he." is another way of saying "I miss you more than he misses you."
In other words, the two sentences are correct. Take note however, that they have two totally different meanings.
More related stuff in the next lesson.
Attribution to Rebecca Elliot and her book Painless Grammar (c) 2006, 1997
Other Pronoun tips:
Pronoun Basics (Pronouns, Part 1 of 5)
Weird Antecedents (Pronouns, Part 2 of 5)
The Confusing "Him" or "He" (Pronouns, Part 3 of 5)
Subjective or Objective Pronouns (Pronouns, Part 4 of 5)
You... Yes, You. (Pronouns, Part 5 of 5)