Government statistics show new graduates' incomes dropped last year for the first time since 1998.
People who finished a tertiary qualification in 2008 earned an average of $33,000 last year, down from more than $34,000 the preceding year.
Those with master's degrees or doctorates and those over 35 were the only new graduates who earned more last year than graduates who entered the workforce in 2008.
Statistics New Zealand says the recession is behind the 2.5 per cent fall, but it does not yet know if incomes dropped this year as well.
It says, however, that tertiary education still pays off because graduates earn more than those who do not complete their qualifications.