In an effort to transition students to college, I don't check homework for my seniors in math class. Well, I don't blatantly check their homework by walking around the room and looking over each student's shoulder while marking in a grade book whether it's done or not. But, seriously, I'm in the same room, kids. I'm 15 feet away. Do you really think I can't see that your notebook page is blank before you frantically scribble down every problem I go through so that the students who actually did their homework can find out what they did wrong? Anyway, if a kid can pull of an A without doing the homework assignments, more power to him; the homework would have been busy work. That's pretty rare though.
Usually, I'll get a kid or two each exam who is new to the whole slacking off thing. My test grades usually run like this: 70% of the class 90%+, then an 80-something, a 70-something, and the rest fail. Without fail, when I call the students out who failed, it's because they didn't do their homework. "Look around. Almost everyone got an A. The only people who failed are the ones who didn't do their homework. Do you think your college professors are going to hold your hand and check your homework for the first 5 minutes of every class?" I usually give kids one or two extra chances a year to take a retest, provided they make up the homework first - and I point out that "next year, this would be a $1500 lesson, because college professors are too busy to give you a second chance."
Most of the kids learn their lesson. One of these days, I'm going to present parents with a set of statistics: those who never learn the lesson that homework = success, and fail 3 or more tests during the year, inevitably fail out of college within the first year. Nearly without exception. (I say "nearly without exception", but I've been thinking and can't think of any exceptions. Last year, it was two students. Both failed out of college.