Perhaps Labour was onto something with the 'man-ban'.
New research looking at 125 different countries has found having women in Government significantly reduces corruption.
Though the link has been noted before, the researchers say this is the first time it's been proven that women's presence causes corruption to decrease, rather than women being attracted to roles in which there already is a lower amount of corruption.
"This research underscores the importance of women empowerment, their presence in leadership roles and their representation in government, said Sudipta Sarangi of Virginia Tech, who led the study.
"This is especially important in light of the fact that women remain underrepresented in politics in most countries, including the United States."
The researchers say the reduced amount of corruption has to be a result of women's policymaking decisions, because companies and other private organisations don't see the same benefit when they hire more women.
"These results do not necessarily mean that women are inherently less corrupt. In fact, their findings suggest otherwise," the study, published in the Journal of Economic Behavior & Organization, said.
"If women are indeed less corrupt, then there should be a significant negative correlation between all these measures of female participation and corruption."
In 2013, Labour considered only nominating women as candidates for some seats, in an attempt to get a gender balance in its caucus. The 'man-ban', as it was dubbed, shot down by then-leader David Shearer. His replacement, David Cunliffe, apologised for "being a man", and was ridiculed by then-Prime Minister Sir John Key.
Politics isn't a business
So what is it about women that leads to less corruption in politics, but not business?
"An extensive body of prior research shows that women politicians choose policies that are more closely related to the welfare of women, children, and family," the study said. "Previous research has established that a greater presence of women in government is associated with better education and health outcomes."
The research also found bribery of politicians was less common in countries with more equal gender representation.
In February, New Zealand was once again ranked the least-corrupt country in the world by Transparency International. Forty-six of our 120 MPs are women - 38 percent, the highest in our history.
Only six countries have a female-majority government, according to Inter-Parliamentary Union - Bulgaria, France, Nicaragua, Sweden, Canada and Slovenia.
Only one-in-five members of the US Senate and House are women - the US was ranked 21st least-corrupt by Transparency International.
Somalia, ranked the most corrupt country in the world, has recently implemented a 30 percent female quota for its parliament - though women still face barriers to election. MPs are voted in by delegates chosen by a few dozen "traditional leaders" - all of whom are men.
Several countries have only a single-digit percentage of women in their governments, including Yemen, Qatar, Haiti, Tonga, Thailand, Iran, Bahrain, Lebanon, Papua New Guinea and Nigeria. Of those, only Qatar is ranked inside Transparency International's top 30 least-corrupt countries.