Often times I see that people won't down vote "bad" responses/answers because they don't want to consistently lose rep.
Sure, it's only -1 point per down-vote, but do this 3 - 5 or so times a day, and you'll see that you've lost 1,095 - 1,825 reputation (assuming that you log in and do this every day) in the past year.
I thought of a few similar solutions to this:
Provide users with a reputation of at least 125 (minimum to down-vote) the ability to down-vote 3 times a day without a penalty to their reputation. OPTIONAL: If you are the recipient of a down-vote that was cast free, you will only lose -1 reputation.
Provide users with a reputation of 500 (this number is only my suggestion, it really could vary) the ability to down-vote 3 times a day without losing any rep. Then perhaps at 5,000 reputation, users may have 5 or 10 free daily down-votes (who would down-vote any more than 10 times a day anyways? That must be an awful day if you have to do that!).
Those are only a few options, but I think something to give down-voting a slight promotion (but not so huge of a promotion that everyone will start getting reckless with it/abusing its power) would be nice to see. This slight promotion may convince more users to down-vote answers/responses (and maybe even questions, although I've been told down-voting on questions is already free) that they see useless, repetitive, uninformative, etc. Does anyone else have any other ideas to add to this?