The short-changing affects more than nine in 10 workers younger than 18 and hits women harder than men, according to superannuation peak body the Super Members Council. The law was denying young workers guaranteed contributions at a key point in their careers, the council said. A 16-year-old worker might miss out on up to $2500 in super contributions by the time they reached adulthood. "Small businesses are already managing rising employment costs, increasing compliance obligations and tight operating margins," the council's chief executive Skye Cappucio told AAP. The jobs market for teenagers could shrivel up if young workers were more expensive to hire or if additional costs squeezed small businesses, the coalition argued during the Senate debate.