A new study has revealed that the population in the United States is more than that of Europe despite having lower life expectancy because of higher birth rate and immigration.
In 2005, the population of the then 25-member European Union stood at 463 million people against 296 million in the United States, noted the study by France's national institute of demographic studies (INED).
But over the past 20 years the US population has grown three and a half times faster, wrote demographer Gilles Pison in the report published in INED's "Population and Societies" journal.
By 2050, Europe could see its population fall to under 460 million while the United States could grow to 402 million, according to UN projections.
That is due to several factors, said INED. The birthrate is much higher in the United States, with 14 births per thousand people against 10.5 per thousand in the EU.
That makes the United States "part of humanity's most fertile minority," the report said.
Widespread religious practice in the US, more unplanned pregnancies, and the large Hispanic minority, with 2.9 children per woman, also help explain the difference in population growth rates.
To that is added growth due to immigration, said INED.
In Europe, "if the population continues to grow, it is due solely to immigration," said the study.
But life expectancy is higher in the EU.
In 2005, European women lived to an average of 82 years while American women lived to 80.4 years. European men lived to 75.8 years while their US counterparts lived to 75.2.