It is changing behaviours and it's changing a mindset. When I was growing up there were no domestic assault laws. Now there are domestic assault laws. The way my sons grow up and the way men treat women in this country is different because of those laws. Laws set a trajectory in the way we want our country to go.
So if we criminalize the purchasing of sex we are changing the trajectory in the way this country is going and saying men can no longer sexually subordinate women any longer for their own benefit.