This is long, sorry but if you are interested you can Google 'how New Zealand prostitution laws actually hurt women' you will get a document called "Does Legalizing Prostitution Protect Women and Girls?"
The first bit says...
"DOES LEGALIZING PROSTITUTION PROTECT
WOMEN AND GIRLS?
Findings from countries and states where prostitution is legal
Millions of women and girls around the world are exploited in the commercial sex industry (i.e. the buying and selling of sex), which is often the end destination of sex trafficking. While human rights activists, government officials and the United Nations all agree that the trafficking of women and girls for prostitution is a serious – and growing – problem, there is disagreement as to the best way to prevent trafficking and exploitation. Some believe that targeting the demand for commercial sex that fuels sex trafficking while decriminalizing those exploited in prostitution is the most effective way to curb sex trafficking, while others argue that legalizing or decriminalizing the commercial sex industry is the best way to weed out and prevent exploitation and trafficking.
The legalization of prostitution includes legalizing the activities involved in and surrounding prostitution, and often imposing regulations specific to the sex industry. Countries and states that have legalized prostitution include: Senegal (1969), states in Australia including Victoria (1994) and Queensland (1999), the Netherlands (2000) and Germany (2002).
The decriminalization of prostitution includes repealing all laws or provisions against prostitution, and not imposing prostitution-specific regulations. Countries and states that have decriminalized prostitution include the Australian state of New South Wales (1995), and New Zealand (2003).
SEX TRAFFICKING AND EXPLOITATION OF WOMEN AND CHILDREN
NETHERLANDS: In 2003, the Amsterdam Mayor stated that legalization had failed to prevent trafficking, saying “it appeared impossible to create a safe and controllable zone for women that was not open to abuse by organised crime.”i In 2007, a government report noted that “pimps [i.e. traffickers] are still a very common phenomenon.”ii
NEW SOUTH WALES (AUSTRALIA): One police officer who investigates sex trafficking commented on the effects of decriminalization: “Although the intention was to provide a safe working environment for sex workers the reverse has occurred in that pimps and brothel operators were empowered and enriched.”iii
NEW ZEALAND: The government noted that the law that decriminalized prostitution “cannot in itself prevent or address the causes of under age prostitution.”iv The National Council of Women of New Zealand, which originally supported decriminalization, expressed their concern that “we are still seeing girls as young as 13 and 14 on the streets selling their bodies,” and that men arrested for buying sex from minors are receiving light sentences under the law.v"
I won't paste any more of it in but you can see just from the introduction that legalising prostitution does not necessarily empower women or make things safer!!!