The average skill of workers has been falling in New Zealand, an economic researcher says.
Motu Research said strong employment between 2001 and 2012 attracted a disproportionate number of lower skilled workers, which diluted the increase in average skill due to ageing and rising qualifications.
The research company said the fall in average skill was more pronounced in the years before the global financial crisis, when the economy grew strongly.
While average skills increased due to people gaining experience and a rising share of those with tertiary qualifications, that was more than offset by an influx of new workers with lower skills than those already in New Zealand.
That was partly reversed from 2008 onwards, as firms laid off less productive workers.
Motu said it provided part of the explanation for New Zealand's generally low productivity growth.