in March 2007 to abolish the one-child rule, citing "social problems and personality disorders in young people". One statement read, "It is not healthy for children to play only with their parents and be spoiled by them: it is not right to limit the number to two children per family, either." The proposal was prepared by Ye Tingfang, a professor at the Chinese Academy of Social Sciences, who suggested that the government at least restore the previous rule that allowed couples to have up to two children. According to a scholar, "The one-child limit is too extreme. It violates nature's law and, in the long run, this will lead to mother nature's revenge." Birth tourism Reports surfaced of Chinese women giving birth to their second child overseas, a practice known as birth tourism. Many went to Hong Kong, which is exempt from the one-child policy. Likewise, a Hong Kong passport differs from China's mainland passport by providing additional advantages. Recently though, the Hong Kong government has drastically reduced the quota of births set for non-local women in public hospitals. As the United States practices birthright citizenship, all children born in the US automatically have US citizenship at birth. The closest US location from China is Saipan in the Northern Mariana Islands, a US dependency in the western Pacific Ocean that generally allows Chinese citizens to visit for 14 days without requiring a visa. As of 2012, the Northern Mariana Islands were experiencing an increase in births by Chinese citizens, because birth tourism there had become cheaper than in Hong Kong. This option is used by relatively affluent Chinese who may want their children to have the option of living in the US as adults. Sex-selective abortion Due to the preference in rural Chinese society to give birth to a son, prenatal sex discernment and sex-selective abortions are illegal in China. Often argued as one of the key factors in the imbalanced sex-ratio in China, as excess female infant mortality and underreporting of female births cannot solely explain this gender disparity. Researchers have found that the gender of the firstborn child in rural parts of China impacts whether or not the mother will seek an ultrasound for the second child. 40% of women with a firstborn son seek an ultrasound for their second pregnancy, versus 70% of women with firstborn daughters. This represents a desire for women to have a son