Depends upon one's definition of "effective" as that will decide the winner of this mini-competition.
And the threat.
And the distance.
And the immediacy of the requirement.
And the requirement.
Etc.....etc....etc.
Didn't mean to be flippant but there are no winners or losers in these things, they each have differing capabilities. Think of one scenario and one will be more effective, think of another and the other will be.
And who's Harrier are you talking about? USMC? Spanish? Italian? Indian? If they each still have them?