Prostitution is the promiscuous bartering of sex favours for money or gifts. Most prostitutes are females serving male customers, the next largest group are male prostitutes serving homosexual clients. There are some male prostitutes who serve female customers and a few female prostitutes who have lesbian clients. In some countries prostitution is a crime; in others it is legalized in so far as all prostitutes must be registered and submit to regular medical examinations to check for venereal disease. Where it is illegal, prostitutes are usually subject to intimidation and extortion from pimps or organized crime. Prostitutes often blackmail their clients or rob them. Social stigma may prevent prostitutes from becoming rehabilitated into normal life.
Prostitution is closely related to urban life and mobile populations. In primitive tribes it is virtually unknown, although promiscuity before marriage, and polygamy or polyandry, may be accepted. Economic factors are important reasons for going into prostitution, which is often very marked in poverty stricken areas where there is little employment for either men or women, or among indigenous tribes which have suffered cultural invasion and have not been able to adapt economically to a new way of life. Frequently there are social reasons also; broken families, disgrace that comes with abandonment by a boy friend, pregnancy and single parenthood, encouragement or outright sale by parents and violence in the family. Prostitutes may be very young and coerced into prostitution. Children who are gaoled for vagrancy are bailed out by recruiters of prostitutes and forced into the trade. So-called employment agencies recruit women from poor areas, promising jobs, paying their parents in advance and then forcing them into prostitution.
In Babylon, Cyprus and among the Phoenicians and in parts of western Asia, women prostituted themselves as a religious duty at the sanctuary of a goddess. Prostitution was a means of earning a dowry in some ancient cultures. Prostitutes existed in the ancient Greek and Roman civilizations. In the Middle Ages they were tolerated as the lesser of evils, although efforts were made to check the practice; the Church made attempts to reform and rehabilitate prostitutes. Restrictions on prostitution increased after the Renaissance and became more formalized with the creation of police forces in the 19th century. Until after World War II, the sale of extramarital sex was highly institutionalized in Japan; government officials legally recognized and attempted to supervise brothels from the 12th century on. Prostitution was and still is unknown in many so-called 'primitive' societies, but is found today, to varying degrees, in most cultures and in all parts of the world, especially where the population is very dense and where money changes hands frequently.
One can approach prostitution from the angle of ethnology, sociology or cultural history. From the point of view of political economy, one can see the world of prostitution as a closed economic system; or, from the point of view of criminology, as a branch of the criminal world because of the procuring involved. Prostitution can also be judged by the standards of public health, religion or morality. From the human rights approach, prostitution can be considered as a form of slavery: like slavery in the usual sense, prostitution has an economic aspect. While being a cultural phenomenon rooted in the masculine and feminine images given currency by society, it is a very lucrative market. The merchandise involved is men's pleasure, or their image of pleasure, and is supplied by physical intimacy with women or children. Thus, the alienation of the person in prostitution is more far-reaching than in slavery in its usual sense, where what is alienated is working strength, not intimacy.
Prostitution continues to spread and, along with it, the exploitation of prostitution. In one country studied, about 10% of women aged between 15 and 30 live from prostitution; in another, the proportion of prostitutes in the female population of the capital is over 13%. In yet another country, a government decree allows for the registration of prostitutes, yet offers them no financial protection. Prostitution is beginning at an increasingly younger age.