The government's new $4 billion wage subsidy will offer double the handout to businesses that employ people in their teens and 20s over those in their 30s as part of a bid to get almost half a million unemployed back into work.

Budget papers show the hiring incentive for young people announced on Tuesday amounts to $200 a week for workers aged 16 to 29, or up to about $10,000 a year, but will fall to $100 a week for those aged 30-35.