I wasn't even talking about it until you brought it up.
The ratio of upvotes to downvotes means that, either per-user or in aggregate of the whole system, how often is an upvote used relative to a downvote. If its 100%, then only upvotes are used. If its 90%, then for every 9 upvotes there is on average 1 downvote. And so on.
My opinion and argument in both of my comments is that the number of downvotes, relative to upvotes, should be higher (i.e. more downvotes) as it creates a more healthy ecosystem.
I never talked about enforcing -- it's about incentives (or lack there-of). I strongly encourage you to re-read my comments.
Long live the n2!