I raise for an unsuited AK hand aswell, but not as much as i do for the suited AK. I play according the probability, and once again t he table position; a suited pair has a slightly higher probability. The reason "I' beleive that there should be a large raise with a short stack is because you have less to lose and need more to gain before the blinds eat you; you already have less chips than most players, but you want to play it safe, which is why you raise and eliminate limpers.. Since less players will call ( my goal is usually just one) your opponent(s) have a lower probability to make a pair. Thus, you would have a higher chance of having a high card than them.