Doubters Challenge Report that Illegal Immigration is Twice as High as Traditional Estimates

September 28, 2018 | Joe Guzzardi

“The number of undocumented immigrants in the United States: Estimates based on demographic modeling with data from 1990 to 2016,” a new study published in the peer-reviewed science journal, PLOS ONE, found that the illegal immigration population in the United States has been, for years, dramatically underestimated.

Using “standard demographic principles of inflow and outflow” and applying the best available and newest data for the period studied, authors Mohammad M. Fazel-Zarandi, Jonathan S. Feinstein and Edward H. Kaplan arrived at a conservative estimate of 16.7 million illegal immigrants in the U.S. for 2016, and a mean estimate of 22.1 million.

The study, which put the illegal immigrant population at roughly 50 to 100 percent higher than the frequently referenced 11 million estimate, stunned immigration think tanks. The Migration Policy Institute and others questioned how the Census Bureau, the American Community Survey and the National Center for Health Statistics could have overlooked some 11 million illegal immigrants in their population estimates. As MPI put it, “people leave footprints.”

To grassroots immigration skeptics, however, the study’s findings are consistent with their own informal, from-the-front observations. How, immigration critics wonder, could the illegal alien population remain fixed for years at roughly 11 million? The static number certainly seems questionable, given that for decades Republican and Democratic administrations alike have tolerated loose borders, endorsed catch and release, and discouraged interior enforcement.

Whether the illegal immigration population is 11 million, 22 million, somewhere in between or even more, the large number of additional people has a direct effect on U.S. jobs and, rarely discussed, the fragile American environment.

Illegal immigrants, we are often told, come to the U.S. in pursuit of a better life. That generally means adopting an American lifestyle, which is highly consumptive. More people in the U.S. means more consumption and more development. Natural habitat is increasingly lost for more housing, highways, schools, hospitals, stores, restaurants, offices, roads, parking, waste and all the other infrastructure needed by ever-more people. Ultimately, more growth in America means more sprawl and less open space, which means less biodiversity.

Since the first Earth Day in 1970, celebrated during President Nixon’s first term, the U.S. population has increased from 203 million to nearly 329 million in 2018. Looking ahead, the Pew Research Center projects that the U.S. population will reach 441 million by 2065, 88 percent fueled by immigration and births to immigrants.

Two Oregon State University scholars, Paul Murtaugh and Michael Schlax, co-authored a groundbreaking study, “Reproduction and the Carbon Legacies of Individuals,” that added an important perspective to the immigration debate.

According to the research of Murtaugh and Schlax, the average carbon footprint of a Mexico resident is 3.67 tons per year; in the U.S., it’s 20.18 tons. Approximately 5.6 million Mexican illegal immigrants currently reside in the U.S. If humans are indeed the major climate change driver, then logic dictates the solution is fewer people in a country with a high carbon footprint and not more.

The Murtaugh-Schlax study demonstrated that a family choosing to reduce the number of children by one could achieve a lifetime CO2 emissions savings of 9,441 metric tons. Contrast this to that same family electing to increase their car’s fuel economy from 20 to 30 mpg. Improving mpg would result in a savings of only 148 metric tons.

It should be obvious that no amount of recycling, energy efficiency or smart growth will restore America to a sound, sustainable place environmentally.


Joe Guzzardi is a Progressives for Immigration Reform analyst who has written about immigration and population for more than 30 years. Contact him at

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terrific writings Joe


Great Article! I might add, however, that there are additional reasons that suggest that numbers of illegal immigrants are higher than the 11 million usually stated. First whatever evidence the 11 million estimate is based on can’t be objective or a sufficiently large, or an unbiased statistical sample because our political class at the direction of their wealthy business owner campaign contributors have made nation spanning ‘sanctuary city’ efforts to NOT RECORD all manner of official contacts with illegals in this nation. Numerous reports in the press have indicated that local and state police regulations or procedures often have no record keeping provision for recording citizenship status of arrests and contacts, and there is no uniform federal requirement for local or state law enforcement to report whatever illegal arrest or incarceration information they do record to one central federal agency either. Also a law enforcement friend here in California has described to me what is in effect the state of paralysis that arrested illegals cause by refusing to give a name or country of origin, and or giving multiple aliases that are all wrong. And of course this use of fake names, stolen social security numbers and identities goes on at all levels of government, at schools and at welfare and free health clinics and our government workers have no choice but just to go along with the whole charade. Some have stated in the press that they would be fired for denying the impoverished services and care if they gave obvious liars a hard time or demanded real identities. Then both parties have for decades resisted any attempt by the census bureau to set up a, in line with the latest sampling and statistical techniques, methodology for determining accurately what the US population is and what groups it consists of. So again there is the fundamental problem of there being no good data to make an total illegal population estimate with. And of course that suits the purposes of the open borders, want to pay slave wages to many millions of illegal workers business owner “few percent” who have until Trump managed to buy off most of our political class to make sure the democratic majority never finds out the real total of illegals in this nation are. For if for example it were credibly determined to be lets say 20 million (which has been stated as a possible high estimate) or perhaps even 30 million then our 1% probably would not be able to withstand the citizen outrage, and their unearned profits gravy train supply of slave wage workers who citizens have to keep just barely alive via taxpayer “top offs” would come to an end. To give readers some idea of the magnitude of the wealth transfer from not rich taxpaying American citizens to our few percent business owner elite its admitted by ‘liberal’ news outlets that 40% of immigrants in California are on various kinds of government assistance (food stamps, housing assistance, free medical care, low income tuition assistance ………) These many programs are by the way are in addition to the usually not mentioned several thousand dollars a year it costs K – 12 to educate the child of most immigrants who make such low wages that they don’t pay much or any income or sales tax, and don’t own a house and so also don’t pay property taxes that usually fund education. And again all these many contacts in order to get ‘free’ money out of American citizens that immigrants avail themselves of are not recorded in any systematic way either – so current estimates are very likely low, for again this essentially all intended because it serves the interests of our business elites.


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