This seems to have turned into, "What's an appropriate amount of support for your young adult child?"
First, to those who say you won't give your kids an allowance, I'd say you're planning to miss out on a great learning experience. The key is to give the kids enough allowance that they can afford a small treat . . . but little enough that big treats require saving. AND at the same time, you make them responsible for some of their own necessities, purchased, of course, from their allowance. This means that they have to remember, "I'm going to need pencils for school" and forego buying a pack of candy. They'll mess up -- most kids have to mess up multiple times before they understand delayed gratification -- but if you don't bail them out, they learn from their mistakes. Failure to have pencils isn't a make-or-break situation, so it's much better to provide that learning opportunity than to wait 'til they're making larger decisions that have bigger consequences. Allowances can be tied to chores, though small children don't seem to make the connection very well. Around 10 kids are ready to see that work = allowance = things I need and want; prior to that age, it's a bit fuzzy -- they can get work = allowance OR allowance = things, but their brains are still in the concrete operations phase, and they just can't quite make the jump yet to see the big picture.
If you don't give an allowance, the other option is to buy the things your child needs when he needs them -- I'm thinking of small children here; if you wait 'til they're old enough to work outside the home, you're already too late. Where's the learning experience in that? They learn that sometimes you say yes, sometimes you say no. They need to control a small amount of money for themselves to internalize the value of a dollar. They need to experience success and failure in small terms so that when they're teens and they do get that first job, they're ready to handle a little more.
As for kicking my kids off my phone plan, why on earth would I do that? We have the old-fashioned X amount for the first phone, $10 each for the second, third and fourth phones. So I would only save $10/month by denying my college student a phone. If she got a phone on her own, it'd cost her much more than that. We're getting good value for the money right now, and we're never anywhere near using all our minutes. As far as I'm concerned, if she wants to stay with this level of service, she can stay on our plan after she finishes college. At that point I'd want her to give us $120/year for the service, but I've spent a great deal of effort pushing the concept of spending on things that're a good value, and I don't see bad value here.
Some of you seem intent upon the idea that you should pay essentially nothing for your adult child -- kick them out into the world, let them learn independence, let them suffer a bit. While I'm not suggesting that you should spoil them and attempt to insulate them from the realities of the world, that's a bit extreme. If you want your child to go to college (or other post-high school training), it's probably going to cost money. It's probably going to cost more money than the adult child is able to pay without going into debt, and debt is one of those things that you don't realize is a mistake until it's too late. Instead, it's better to provide enough help that the student -- with plenty of hard work -- can bridge the gap and graduate without debt. Example: My college daughter's tuition is roughly 7K/year. Say she worked at $8/hour. It'd take her 875 hours (almost 22 weeks of full time work) to earn that tuition. That's pretty tough for a full-time college student: With taxes, it's essentially working full time every week of summer AND working part-time during the school year AND never spending a penny on anything except tuition. It's ignoring textbooks, transportation costs, and living expenses Instead of saying, "You're an adult now -- go figure it out, hope you do okay", it's better to work together to figure out what the student can do to pay a portion of the cost and you, the parent, help make it possible. That might be letting the student live at home, and he pays tuition. It might be paying his tuition and dorm while he pays his books and meal plan.
Yes, a senior should be paying more than a freshman. A young adult should progressively work towards financial independence, but I can't buy into the "You're an adult now, and I trust you'll figure it all out" idea.
People on this board like to use Millionare Next Door as a defense against helping ease their young adult children into full adult responsibilities. If you read the portion that addresses helping your children, you'll see that it definitely cautions against doing too much for them: Basically it suggests that you should not pay your children's necessities (i.e., rent and car payments) so they can afford luxuries (i.e., vacations) -- that allows them to believe they can live a more expensive lifestyle than is actually possible -- but it also gives examples of parents who have helped their children appropriately -- for example, the guy who started Kinkos. It also says that among people who have become financially successful, the most common financial help they received from their parents (as adults) was help getting through college.