The United States could aim to have largest population in the world before the end of the century, thus ensuring its power.
The US now has a population of 316 million - third largest after China, 1.36 billion, and India, 1.28 billion - and could aim for 1.6 billion, simply by opening wide its doors to immigration from across the globe as it did during most of its 237-year history.
If immigration to America were increased to 10 million immigrants per year throughout the remainder of this century, the demographic result would be a US population of about 940 million by 2060 and 1.60 billion by the close the 21stcentury (see Figure 1). The world's second and third largest populations in 2100 are projected to be India, 1.55 billion, and China, 0.94 billion.
However, if in the coming decades America continues with net immigration of about 1.2 million annually, as currently assumed, the US population would reach 420 million by year 2060. Although this projected growth would be an increase of more than 100 million, the US population would fall to fourth place as Nigeria takes over the number three position with a projected population of 460 million in 2060. The populations of the three countries currently larger than Nigeria - Brazil, Indonesia and Pakistan - are expected to peak around midcentury and begin declining thereafter due to projected low fertility rates falling below replacement levels. Also in the longer term, the gap between projected US population, with 1.2 million immigrants annually, versus the larger US population, with 10 million immigrants annually, widens rapidly, resulting in a difference of 1.1 billion Americans at the close of the century.
Immigration is the chief source of America's population growth in the coming decades, unlike China, India and Nigeria. US fertility hovers around the replacement level of about two children per woman and is unlikely to change significantly in the foreseeable future. If immigration were to cease altogether, the US population in 2060 would grow to 355 million, an increase of 39 million, but the labor force would decline by several percentage points and the age structure would be considerably older.
America could easily accommodate a larger population given its considerable size and abundant resources. A population of 1.6 billion would increase the nation's density from today's 33 persons per square kilometers to 165 persons in 2100, about half the level in Massachusetts today. This future density is well below current densities in Germany at 231 per square kilometer; Japan, 335; and the United Kingdom, 255. Even if the world's entire population of 7.1 billion were to reside in America, the nation's resulting density of 732 persons per square kilometer would still be less than current densities of Bahrain, at 1,818; Bangladesh, 1,033; and Singapore, 7,447.
Increased demands for food, housing and energy could be handled with a revitalized US economy and developing underutilized land and natural resources, including natural gas and renewable sources of energy. Innovation and technology could alleviate negative environmental impacts, as has been demonstrated over the nation's two-century history.
Increased immigration is consistent with America's admired tradition of being a nation of immigrants and the eloquent call on the plaque inside the pedestal of the Statue of Liberty: "Give me your tired, your poor, Your huddled masses, yearning to breathe free, The wretched refuse of your teeming shore."
Since the nation's founding in 1776, immigration has accounted for more than half of America's population growth. Without its past immigration waves, America's current population of 316 million would be about 143 million.
Immigrants have shaped American history. At the start of the 20th century, the US proportion of foreign born reached its peak near 15 percent. Considerably higher proportions of foreign born occurred in California, with 25 percent; Massachusetts, 30 percent; Minnesota, 29 percent; and New York, 26 percent. Today, the proportion of foreign born is 13 percent - leading states are California, 27 percent; New York, 22 percent; and New Jersey, 21 percent. Countries with higher proportions of foreign born include Australia, 22 percent; Canada, 21 percent; and Israel, 40 percent.
Rapid population growth for the United States is not without historical precedent. For example, between 1813 and 1900, America's population increased nearly tenfold, 8 million to 76 million, and fivefold between 1890 and 2013, 63 million to 316 million. The populations of some individual US states grew more rapidly than the nation as a whole. For instance, between 1850 and 1910, populations of Texas and California increased 18-fold and 26-fold, respectively.
Increasing US immigration to 10 million per year would facilitate the reunification of separated families. Rather than having to wait for years, US immigrants would be joined by spouses, children, siblings, parents within weeks. This would boost American leadership in promoting family and social networks. America's ethnic, cultural and personal ties, such as those now firmly established with Ireland, Israel and Italy, would be extended to encompass all nations.
The issue of illegal immigration would no longer be a sensitive political matter occupying valuable time and resources of the US president or Congress. Unauthorized immigrants residing in the US - 60 percent currently from Mexico - would be granted amnesty and welcomed as new citizens. Enforcement, border patrol, legal/judicial hearings, incarceration and deportations would be negligible, saving the nation billions of dollars that could be used for rebuilding America's ailing infrastructure.
In addition to the familial, political and administrative advantages, opening America's doors wide to immigrants would engender many far-reaching economic and social benefits, including yielding a vastly expanded GDP and greater tax revenues; more workers, entrepreneurs, innovators and consumers; a younger population; a more competitive workforce and wage levels; increased contributions to Social Security and Medicare; a larger pool of potential recruits for all kinds of work; and enriched cultural diversity.
Furthermore, setting US immigration at 10 million per year would help repopulate and rejuvenate many declining and financially strapped cities, including Detroit, Newark or Stockton. It would ease the labor-shortages for farmers, food producers, working mothers, landscapers, health care providers, high-tech entrepreneurs and more. Energetic immigrants would take on jobs that Americans find difficult, decline to do or are not qualified to perform.
Businesses, chambers of commerce, unions, religious institutions, immigrant-advocacy groups and various government agencies would also benefit from increased immigration. Companies could choose from a terrifically expanded, motivated and youthful labor pool. Unions would have all workers authorized to participate in the labor force, thereby ending the undercutting of fair wages. Government authorities and employers would not need to verify or monitor work permits and worksites except to ensure that all employees pay required taxes.
Global opinion polls show that many people at virtually all skill levels would like to emigrate, and the number-one destination is overwhelmingly the United States. In addition to promoting continued migration from neighboring Canada, Mexico, Central America and other Latin American countries, greater numbers of bright, ambitious and innovative immigrants should be sought from countries in South and East Asia, the Middle East and Africa.
Finally, with US immigration increased to 10 million per year, the enhanced America with a population of 1.6 billion by century's close would mean a more secure and flourishing world. As the world's most populous nation by 2100, America would strengthen its capacity to continue promoting democracy, freedom and development, thereby ensuring peace, stability and prosperity for every region of the world.