is 118:100 (boys:girls), higher in rural areas such as Guangdong and Hainan (130:100) compared to the average of 104:100 in developed countries. It is believed that the ratio would increase further to the point that, by 2020, men of marriageable age would be unable to find mates, resulting in large social problems. Some nations, such as India, have attempted to curtail these gender imbalances with criminal statutes. In contrast, bioethicist Jacob Appel of New York University has argued that governments should pay couples to choose to have female children. According to Professor Appel, "if female babies [were] worth their weight in rupees and yuan, economic and educational opportunities for girls would soon follow." In contrast, actual experience in Western cultures provides no evidence for any degree of gender imbalance from technologies which have long been available and legal – such as selective abortion or preimplantation embryo testing. When used for family balancing indications in such countries as the United States, pre-conceptual sex selection is widely sought without any preferential selection of males. A 1993 survey of more than 2300 pregnant women in the British population found no overall preference for either sex. These findings are largely consistent with other surveys conducted in the US. Thus the right of individual families to determine whether or not to balance gender of offspring in their families is not and will not become, in many countries, a demographic issue. Furthermore, in countries where such demographic issues exist because of strong gender preferences in a segment of the population, regulatory and legal control of, without denial of access to, sperm sorting technology can be utilized to provide individuals with choices while ensuring that equal numbers of boys and girls are produced for population demographic equality. History and folk beliefs Sex selection is not new. There are a wide variety of social sex selections methods which have not been demonstrated to be effective. Because even implausible and ineffective methods have a success rate of 50%, many continued to be recommended by word of mouth. The Greeks and Romans did not have a consistent theory of how sex was determined. Pliny the Elder claims that tying the right testicle of a ram will cause him to produce only females, but does not claim this about other creatures. Pseudo-Plutarch lists many Greek theories of sex determination, including heat and cold, left and right testicles, left and right sides