The so-called kiddie tax, once applied only to children under the age of 14, will hit all young people 18 and under and full-time students up to age 24 starting in 2008. The new rate for unearned income hits wealthy parents who plan to gift stocks to a college-age child who could then sell shares, paying a capital gains tax rate based on the student’s low income. The law will now require that the students pay their parents’ tax rate on such sales. The government expects the change to amount to an extra $1.5 billion in tax revenues over the next 10 years.