"You have your low-paid cleaner, she has children - because of the low pay she receives she can't feed them adequately; those kids go to school without breakfast; they have less of an attention span, they get sick more often," she says.
"There's a very close relationship between income and educational outcomes, but there's another hidden cost - people are doing two or three jobs and they're not around for their kids and they get ill."
Ms Littman is in Auckland today talking about the successes of the London campaign. She was vice-chairwoman of London Citizens and worked for 12 years on the living wage campaign.
The campaign was largely non-political when it began in 2001. After lobbying big business, the coalition group London Citizens then approached local and central government.
"Once we'd won some living wage victories in the health sector we then won major victories in the building and cleaning industry, in the big financial sector, Canary Wharf in the city. Big banks and financial institutions then applied it to their cleaners.
"Once we had done that we then moved into the political level by asking all of the mayoral candidates in 2004 if they would commit to introducing an official living wage. All of them said yes."
London mayor Boris Johnson has been outspoken in his support of a living wage which is now £8.55 ($15.62) an hour.
Ms Littman says the NZ figure is higher because of substantial tax credits included in the London calculation.