Human nature is partly polygynous. This was repressed by monogamous cultural norms. Female sexual liberty means that female sexual choice will often settle on the same men at the expense of other men. Some dudes will get a rotating harem at the expense of other men. Prostitution was prohibited across the United States in the 1920s when cultural norms were conservative and society very strongly enforced monogamy through culture and law. Since the culture has changed very much since then with regards to marriage -- i.e, women's economic progress making them not need men for survival -- and culture permitting women to be liberated sexually -- the continued prohibition of prostitution can no longer be justified and is harmful to male sexual interests. Many female readers of this board will respond by saying they have distaste for men who have to resort to using prostitutes --as if their distaste should be determinative of policy. An individual could have distaste for single mothers, women who have had numerous partners, the sexual practices of others in general etc etc -- but this distaste is meaningless and should have no baring on the question of expanding sexual liberty.