Immigration adds to population growth as long as more immigrants are arriving than there are U.S. residents leaving the country to live abroad (emigrating). The extent to which immigration is a major factor in U.S. population increase is little discussed, but data from the U.S. Census Bureau (CB) provide that information.
According to CB data, the United States population rose on average annually between 2000 and 2010 by about 2.8 million residents. That was lower than the average annual increase of more than 3 million residents between 1990 and 2000
The foreign-born population (immigrants, long-term nonimmigrants and illegal aliens) rose by an annual average between 2000 and 2010 of about 900,000 residents, and, during the 1990 to 2000 decade, the average annual increase was a bit more than 1.1 million residents.
These numbers suggest that the increase in the immigrant population accounted for about a third of the country's overall population increase. But, actually, the impact of immigration on population increase is greater than that. The reason is that a larger share of the immigrant population is in its child-bearing years than the native-born population and a smaller share is in advanced age. So there is a disproportionate number of births to the immigrant population and fewer deaths. Other factors that add to the disproportional impact of immigrants on population increase include the average family size and earlier age of first birth.
The children who are born in the United States - even to non-residents - acquire U.S. citizenship, so their birth is included in the birth data even though their birth here is due to the migration of the parent. But those births very much impact the rate of population increase. An estimate can be made of the overall impact of immigration on population increase by adding an estimate of births and deaths to immigrants to the NIM data.
A key assumption in estimating the overall share of population increase attributable to the foreign-born population is derived from the fact that in 2010, when the foreign-born population was 12.5 percent of the U.S. population, it accounted for 25 percent of the nation's births. Thus the foreign-born population's share of births was double its size.
On the national level, if this disproportionately large share of births and a lower death rate are combined with the population increase from net immigration, the result is an estimated 68 percent share of the increase for the period 2000 to 2009. Significantly, that share is increasing. For 1990 to 1999 the immigrant share of increase was about 59 percent. And for the most recent 2010 to 2013 period, the immigrant share of population increase was about 75 percent. This share is increasing as the foreign-born population increases. The Pew Hispanic Center projected that 82 percent of U.S. population growth from 2005 to 2050, "...will be due to immigrants arriving from 2005 to 2050 and their descendants." If children born to immigrants already in the country before 2005 were added, that percentage would be still higher.
It is difficult to find an economist, businessman or politician who does not assume population growth is a necessary component of economic growth. They tend to see a growing population as more consumers and more constituents. Similarly, religious leaders see their faith advanced by an increase in the number of worshippers and educators see their careers benefit from growing numbers of students. This view of population growth as a benefit thus represents a vested interest.
It is well established that illegal immigration is a net fiscal burden on budgets at all levels of government. And, even though all workers - regardless of legal status - contribute to the Gross Domestic Product (GDP), it is not clear that the work of immigrants adds to GDP per capita or offsets the fiscal drain. But, even if it were accepted that the population growth from immigration has an economic benefit, that would not mean that faster population growth would be more beneficial than slower population growth. The fast immigrant population growth of a century ago, i.e., "the great wave," had serious drawbacks in job competition, stagnating wages, societal strife, and swelling ghettos-like ethnic urban enclaves. Public opposition to these aspects led to adoption of restrictive immigration in the early 1920s that lasted until 1965. The current surge in foreign-born children challenges,among other things, school classroom space limits and services for non-English speaking students. The nation's social welfare structure also is challenged by newcomers who consume more in services than they contribute in taxes.
The challenge of immigration policy should be to define a level of immigration that does not have an adverse impact on the overall society and on individual native-born citizens. The last national commission appointed to study that issue - the U.S. Commission on Immigration Reform (USCIR) - recommended a reduction in the base level of immigration to 550,000 persons per year. That was a significant reduction from the then annual average legal immigrant admission level of about 850,000 persons. Today, legal immigrant admissions have further swelled to an average of more than one million persons per year.
There are many who would like to see an even greater reduction in immigration than that recommended by the USCIR. The reason has nothing to do with from where immigrants come or their race or religious belief. It results from a long-term perspective that indefinite growth is impossible in a finite world and that in this country we are already seeing the effects of exceeding natural limits. Unfortunately, those who see population growth as a panacea wear blinders to the long-range consequences.
There currently is no realistic alternative in sight to our economy's dependence on finite and dwindling fossil fuels. Instead of battling over how best to exploit those resources, we should be focused on how long they will last. There is a fixed amount of freshwater resources, and both a growing population and agricultural production to feed that population place greater demands on that resource. In some areas the resource is already shrinking because of drought. Elsewhere, water in underground aquifers is being pumped out faster than it is replenished, which means they will run dry at some point. Those resources are vital to agricultural production, so if water resources diminish, food production will be similarly challenged. Population growth also consumes land that could be used for agriculture or recreation and to protect the wildlife that are part of the environment that we bear a responsibility to protect.
Reducing immigration would not be a solution for all of the problems of a growing population, but it would contribute to better management of increasingly overburdened resources. If immigration were reduced to the level of emigration (departing residents), that would significantly reduce the role of immigration in spurring population growth. That level of emigration is estimated to be about a third of a million persons per year. The adoption of annual immigration at that reduced level would still be higher than the level of immigration during the period of restricted entry between 1920 and 1965, but it would contribute to a stable - non-growing - population. Within a few generations - after the baby boom and ripple effects among the native-born population and the effects of the high immigrant birth rate receded - the population could become stable.
U.S. Immigration and Population
State Immigration and Population
Metro area Immigration and Population by state, and alphabetically