Council of Trade Unions economist Bill Rosenberg says personal incomes could get worse before picking up at better levels.
Official figures from Statistics New Zealand in the year to June show median weekly income for all age groups rose 1.8% to $560.
Income levels increased for the 20 to 24, 60 to 64 and 65+ age groups.
Median hourly earning rose 2.4%, or 48 cents, to $20.86.
Mr Rosenberg said most categories remained flat, with more people relying on benefits. He said the forecasts for the second half of the year tend to be downward, so it may get worse before it gets better.
Even though there has been an increase in gross domestic product figures, he said unemployment has increased at the same time, so there is a jobless growth spectre which tends to depress wages.
Mr Rosenberg said there could be a continuation of wages not rising and people finding it hard to get jobs and extra hours.
The ageing population also means more people are going onto superannuation.
"Very likely the employment situation has encouraged people to do that rather than look for jobs," he said.