Why Joe Hockey knows what women really want Shadow Treasurer Joe Hockey and his wife Melissa Babbage. Picture: Ray Strange Source: The Sunday Telegraph JOE Hockey has backed tax deductibility for childcare and broken with Liberal Party policy on the possible need for quotas for women on boards. In an exclusive interview, Mr Hockey said working mums were crucial to productivity. "I argued early on for tax deductibility for childcare and I was slapped down," he said. Tax deductibility for childcare is not Liberal policy but the Coalition has promised a Productivity Commission review if elected. Mr Hockey, who was one of the first male MPs to take paternity leave, said: "Having more women in the workforce increases participation. It's good for corporate balance sheets because the more diverse your workforce, the better the output. Mr Hockey and his wife Melissa Babbage, a former senior banking executive, both said they had an open mind on quotas for women on boards. Ms Babbage said the fact women held just 8 per cent of senior executive roles was a problem. "I think there's a group of senior men that are really trying to show strong leadership in this area who are really supportive of women," she said, adding: "Having said that, the definition of insanity is doing the same thing and expecting a different result."