Supermarket and fast-food giants could be the biggest beneficiaries of the government's new wage subsidy for young people, with the hiring credits potentially reducing their wage liabilities for teenage workers by two-thirds.

Citi analysis released on Tuesday said the JobMaker hiring scheme detailed in the budget was likely to assist high-performing retailers such as Coles and Woolworths, while the Retail and Fast Food Workers Union (RAFFWU) has pointed to McDonald's as a major beneficiary because of its 100,000-strong workforce, largely aged under 21.