Raising the minimum wage to $15 an hour was a start to fixing some of the problems, he said.
But he admitted the cost to employers had not yet been calculated.
When asked what the overall cost would be, he said Labour did not know exactly how much it would cost.
He then admitted he had not costed it, but understood there had "been work done around it".
"I think that we've seen that the millions of the dollars that it will put into the economy of raising the minimum wage will actually have a positive boost, it will have an economic advantage. So we're not talking about costs here. We're talking about boosting the economy," he said.
Last year Prime Minister John Key said the then Labour Department had calculated a lift to $15 an hour would cost 6000 jobs because businesses would probably lay off staff when faced with such steep rises in costs.
A separate bill to Monday-ise Anzac Day and Waitangi Day when they fall on the weekend, also supported by Mr Clark, passed its first reading last week.