United States
The United States has a birth rate of 13 per 1,000, which is 5 births below the world average. Its population growth rate is positive at 0.7%, higher than that of many developed nations. In fiscal year 2016, over one million immigrants (most of whom entered through family reunification) were granted legal residence. Mexico has been the leading source of new residents since the 1965 Immigration Act. China, India, and the Philippines have been in the top four sending countries every year since the 1990s. , approximately 11.4 million residents are illegal immigrants. , 47% of all immigrants are Hispanic, 26% are Asian, 18% are white and 8% are black. The percentage of immigrants who are Asian is increasing while the percentage who are Hispanic is decreasing. The estimated number of illegal immigrants dropped to 10.7 million in 2017, down from a peak of 12.2 million in 2007. In 2017, 33,000 refugees were resettled in the United States. This was fewer than were resettled in the rest of the world for the first time in decades.
A 2017 Gallup poll concluded that 4.5% of adult Americans identified as LGBT with 5.1% of women identifying as LGBT, compared with 3.9% of men. The highest percentage came from the District of Columbia (10%), while the lowest state was North Dakota at 1.7%.
Human sex ratio
Several studies have examined human birth sex ratio data to determine if there is a natural relationship between the age of mother or father to the birth sex ratio. For example, Ruder has studied 1.67 million births in 33 states in the United States to discern effect of parent's age and birth sex ratios. Similarly, Jacobsen et al. have studied 0.82 million births in Denmark with the same goal. These scientists find that maternal age has no statistically significant role on human birth sex ratio. However, they report a significant effect of paternal age. Significantly more male babies were born per 1000 female babies to younger fathers than to older fathers. These studies suggest that social factors such as early marriage and quickly fertile couples may play a role in raising birth sex ratios in certain societies.