just thought i'de chime in.
now i'm older, so when i talk about my experience it was after i graduated highschool in '79.
my parent's household rule was so long as you were going to school FULL TIME, any earnings you made were yours free and clear (you did pay your own gas, auto insurance and repairs if you were employed). if you dropped out, graduated, opted not to go to college, or shifted to part-time schooling you were charged room and board (with the exception of summer session when you were not expected to attend if you did'nt care to). although i was unable for a very long time to find full time work in the career path i graduated from it was the expectation that i pay full room and board (reasoning-i could find full time work or multiple part time jobs to tide me over). my room and board was $300 per month. it was NOT saved to gift me with-it went to the expenses i incurred by living in their home (utilities, food, housing...). it was up front and a known expectation to me. as a result, when i was attending school and working part time i got into the habit of saving a good chunk of each paycheck because i saw how long my peers were taking to find a job post grad-i wanted to have a safety net to cover me on room/board should that happen to me upon graduation.
in hindsight i find it interesting that while mom and dad were hard and fast with this rule with me, they were not so much with any of my older brothers-they would not attend and not be charged, choose to quit a job and not consider the financial consequences cuz mom and dad would'nt charge them. i am the only one of my parent's children that has never moved back 'home' during a job loss or 'hard times'.
i had lots of friends who lived at home while in college and working part time-or lived in the dorms on mom and dad's dime while working part time with no obligation for paying any room or board. the majority did'nt save a penny, and were in for a big shock when they faced renting their own places ('it can't cost that much for utilities', 'i know my mom never paid that much to feed me', 'my landlord is such and s.o.b-i was only a week late with the rent'

...). i felt i was blessed with an education both at school and in my home.
p.s.-the highschool my dd and ds will attend has a mandatory work program for all students in attendance (private school 9th-12th)-the school ensures they line up enough jobs for all the students, and establishes a base wage/hour set up. a flat amount of their earnings (aprox 50%) HAS to go directly into the student's tuition fund (parents can't opt out for their student). the schools reasoning is 2 fold-to educate the students on the physical work that goes to paying for an education, and to provide those who will either pay for their own college educations or those who opt not to go to college with work experience that can aide them in securing employment post highschool graduation. i am very supportive of this.