Dr Parkinson says Treasury "expects growth in living standards to slow over time unless productivity growth improves".
But Mr Shorten argues that doesn't imply people aren't working hard enough now.
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"I don't think Australians are lazy at all," the assistant treasurer told ABC TV.
"I think Australian are very hard working."
Mr Shorten said productivity didn't just mean working harder or longer.
Dr Parkinson was suggesting the country needed to look at a range of factors including the investment of capital, the take-up of new technology and "how do we do what we do and get more out of what we do for the same amount of effort".
"I am upbeat about the future," Mr Shorten said.
"But of course the Treasury secretary said last night we need to keep relentlessly focusing on productivity."
The assistant treasurer said while there was a productivity spurt in the 1990s, generally the former Howard government years involved a "long sleep".
In his speech to a Melbourne conference last night, Dr Parkinson criticised "populist media campaigns such as we have seen recently" for undermining political support for much-needed reform.
