WASHINGTON (AP) — There’s one number that keeps up popping up in the debate over illegal immigration: 11 million.
That’s the ballpark estimate of how many people are living in the U.S. without legal permission.
But how would anybody know that? It’s not like people who are living in the U.S. illegally are jumping up and down to volunteer that kind of information.
Bring on the statisticians!
Number-crunchers dive deep into census data and other government surveys, make a bunch of educated assumptions and adjustments for people who may be left out, mix in some population information from Mexico and elsewhere and tend to arrive at similar figures.
The Homeland Security Department, for example, estimates there were 11.5 million unauthorized immigrants living in the U.S. in January 2011. The Pew Hispanic Center, a nonpartisan research organization, estimates there were 11.1 million living in the U.S. in March 2011. Other estimates are in the same neighborhood.
The demographers rely on what’s called the “residual” method to tease out the data.
That is, they take estimates of the legal foreign-born population and subtract that number from the total foreign-born population. The remainder — or residual — represents those who are living in the country without legal permission.
It’s a fairly simple concept, but there are lots of complex assumptions that go into the calculations: How much to adjust for an undercount of foreign-born residents in the census that’s done once every 10 years? How many foreign-born residents are migrating out of the U.S.? How many die in the U.S.? And so on.
“All of these things tweak the numbers on the margins, but they don’t change the story very much,” says Randy Capps, a senior policy analyst at the nonpartisan Migration Policy Institute. “There’s a pretty good consensus, and I think the numbers are generally accepted on all sides of the debate.”
Pew demographer Jeffrey Passel, who’s been calculating illegal immigration estimates for decades, says the underlying method isn’t all that complicated, but there’s a lot of number-crunching to be done to reach a solid estimate.
“I wouldn’t argue that it’s good to the last hundred thousand, but I think most people think it’s within a half a million,” says Passel.
He tries to clearly lay out how he gets his numbers — to a point.
“My colleagues give me a hard time,” he says, “because when I write a report the methodology section is longer than the report.”
More Related Stories
- 2 more arrested in London attacks
- Glenn Beck: CNN interview with atheist tornado survivor was a setup!
- Incoming BBC news director on journalism gender gap: "We can do better"
- Illegal construction, shoddy materials at fault in Bangladesh factory disaster
- Ahead of Obama's speech, U.S. acknowledges four American drone killings
- Must-see morning clip: Bill O'Reilly visits "The Daily Show"
- Lawsuit alleges anti-gay hiring practices at ExxonMobil
- Boy Scouts poised to vote, still greatly divided on gay youth
- House supporters of KXL received $56m from fossil fuel industry
- 80-year-old becomes oldest to climb Mount Everest
- Before FBI shooting man implicated self, Tsarnaev in triple murder
- Paul McCartney backs Pussy Riot
- UK emergency committee convenes after attack
- Brave scout leader tried to reason with London attackers
- If Alex Pareene were a cable news executive...
- El Salvador court delays ruling on abortion case while woman's life hangs in the balance
- UK officials: Radical Islam behind London attack
- Pa. governor "can't find" any Latinos to work in his administration
- London machete attack could be linked to terrorism
- Conservative group blames military sexual assault on "Don't Ask, Don't Tell" repeal
- Lois Lerner, IRS disaster
Featured Slide Shows
The week in 10 picsclose X
- 1 of 11
Lisa Montgomery embraces her nephew Thursday after a tornado tore apart her home in Cleburne, Texas. The twister killed six people and destroyed entire swaths of the North Texas town.
Credit: AP/LM Otero
Jack McMahon, the defense attorney for abortion doctor Kermit Gosnell, speaks outside the Criminal Justice Center in Philadelphia Tuesday. His client was convicted of killing three babies in his clinic, and will serve multiple life sentences.
Credit: AP/Matt Rourke
A photo taken Monday captures Vice President Joe Biden's response to a Milwaukee second-grader's innovative proposal to end America's epidemic of gun violence. This guy!
Credit: AP/Jenny Aicher
Sen. Rand Paul, R-Ky., flanked by a grouper-eyed Michele Bachmann, addresses the IRS' admission that it targeted Tea Party groups in advance of the 2012 election. In an op-ed for CNN Thursday, the Kentucky senator slammed the president for his faux outrage.
Credit: AP/Molly Riley
Ousted IRS chief Steven Miller is sworn in on Capitol Hill Friday. Miller testified before the House Ways and Means Committee on the extra scrutiny the agency gave conservative groups applying for tax-exempt status.
Credit: AP/J. Scott Applewhite
Attorney General Eric Holder pauses as he testifies on Capitol Hill before the House Judiciary Committee Wednesday. Holder is under fire, among other things, for the Justice Department's gathering of phone records at the Associated Press.
Credit: AP/Carolyn Kaster
O.J. Simpson sits during an evidentiary hearing at Clark County District Court in Las Vegas, Nev., Thursday. Simpson, who is currently serving a nine-to-33-year sentence in state prison for armed robbery and kidnapping, is using a writ of habeas corpus to seek a new trial.
Credit: AP/Las Vegas Review-Journal/Jeff Scheid
Major Tom to ground control: On Sunday astronaut Chris Hadfield recorded the first music video from space, a cover of David Bowie's "Space Oddity."
Credit: AP/NASA/Chris Hadfield
When it rains it pours. President Barack Obama speaks during a news conference Thursday with Turkish Prime Minister Recep Tayyip Erdogan, inexplicably inspiring an #umbrellagate Twitter meme.
Credit: AP/Jacquelyn Martin
A smoke plume rises high above a road block at the intersection of County A and Ross Road east of Solon Springs, Wis., Tuesday. No injuries were reported, but the the wildfire caused evacuations across northwestern Wisconsin.
Credit: AP/The Duluth News-Tribune/Clint Austin
Recent Slide Shows
- 1 of 11