negative, I wouldn't toe nothing in if your wanting a good driving, straight, good tire wearing machine....
having your toe off is what mainly eats your tires
your tires can deflect somewhat(ever see pictures of tires rolled over in hard corners?), so some negative camber isn't the worst thing in the world, sure extreme cases of it, over time or abuse, will show slightly more wear on one side compared to the other.... but your toe will really eat tires much more....
I think for every 1/16th of an inch your toe is off, for every mile you drive its like dragging your tire sideways for 7 feet
but back on topic, I wouldn't try to "reduce" tire wear on my tires because of a slight negative camber by doing something that will reduce the life of your tire even faster......