The March 6 raid at the Michael Bianco factory in New Bedford sparked a heated debate over illegal immigration. This is the second in an occasional series examining how immigration, both legal and illegal, is affecting Rhode Island and its institutions.

PROVIDENCE — They seem like simple questions: How many illegal immigrants live in Rhode Island? How much does illegal immigration cost state taxpayers?

But the answers can’t be found anywhere within Rhode Island government. Despite databases overflowing with information on the state’s welfare, education, health and prison systems, there is no agency that tracks the cost of illegal immigration.

In a debate freighted with emotion, state government’s attitude is: Don’t ask, don’t tell.

When asked by The Journal for information on the cost of illegal immigrants to government-subsidized programs, federal and state agencies and experts could not even make an estimate.

Experts say there is no way of accurately pinning down the economic impact of illegal immigration in a manner that people with differing political agendas on immigration can agree on.

“I think we really don’t know the answer,” says Giovanni Peri, an economist and professor at the University of California-Davis, who has studied the issue and says he knows of no reliable study done by any state. “The hardest number is the fiscal impact. The data on illegals is very spotty … and people tend to cut the data in a way that you see only the positive or only the negative.”

In part, that is because there is no accurate count of illegal immigrants. In the national census taken every decade, the Census Bureau does not ask respondents whether they are here legally. The closest it comes is to ask people whether they were born outside the United States and whether they are citizens.

Because people who are here illegally live in the shadows of society — and can be deported if they are caught — they tend to hide from government agencies that would want to count them.

The Department of Homeland Security uses a formula to estimate how many illegal immigrants live in each state. It starts with the census of foreign-born people in a state. Then it subtracts the non-citizens who have permission to be here legally. Anyone left is counted as an illegal resident.

In 2000, the Department of Homeland estimated that 16,000 illegal immigrants were living in Rhode Island, a number that many other experts consider low. The department does not have a more recent estimate.

William Shuey, executive director of the International Institute of Rhode Island, in Providence, which helps immigrants and teaches them English, says that illegal immigrants probably make up between 2 percent and 4 percent of the state’s population, which is about the national proportion. By that calculation, Rhode Island would have between 20,000 and 40,000 illegal immigrants.

To merely ask what illegal immigration costs taxpayers is to raise hackles from the many sides in a debate that has become increasingly sharp since the March 6 immigration raid on a New Bedford textile factory that employed 300 or more illegal immigrants.

“I really think the state doesn’t want the word out on the true cost of this,” says Terry Gorman, of Lincoln, founder of Rhode Islanders for Immigration Law Enforcement, which lobbies at the State House for legislation that would crack down on undocumented immigration. “I think it is a big cover-up … somebody doesn’t want those numbers out.”

Advocates for illegal immigrants don’t agree. “They don’t cost the taxpayers anything, if you ask me,” says Shuey, director of the organization that helps newly arrived immigrants. “Most all of them work and pay income and sales taxes. Through their landlords they pay property taxes. They aren’t eligible for welfare and other government programs. What next are we going to blame on the immigrants, global warming?”

People who come to the United States illegally are not eligible for most state benefits. But all children, whether they are legal residents or not, are eligible — indeed required — to attend school.

Public schools in Rhode Island do not ask about the citizenship of students or their parents. In fact, school districts are barred from discriminating on the basis of citizenship based on a 1982 U.S. Supreme Court decision in a Texas case.

Rhode Island’s Department of Education does annually report to the federal government the number of immigrant students. It follows the federal definition, reporting on students who have been in U.S. schools for three years or less.

Again, no determination of whether these students are legal residents is made. Rhode Island school districts require students to provide proof of residency in the district, some medical records, such as vaccinations, and a birth certificate or passport, so they can determine how many students were born outside the U.S., although this does not determine which students are here illegally.

With 24,674 students, Providence is Rhode Island’s largest school district. Of that total, 3,885 have what is known as a U.S. entry date, meaning they were not born in the United States, according to city school officials. Last year, Providence provided 5,745 students with some form of English as a Second Language instruction. School officials say English-language learners come from 45 countries, speaking 42 different languages. It costs roughly $13,400 to educate each Providence student, according to state data.

WHEN IT COMES to immigrants, hospitals have much the same attitude as schools — they don’t probe too deeply into immigration status.

Rhode Island hospitals and nonprofit health care centers are obliged by their charters, nonprofit status and an array of state and federal laws to take care of every sick patient who shows up.

The mission of a hospital, says Edward Quinlan, president of the Hospital Association of Rhode Island, is to provide care to all who need it. Hospitals resist asking questions that might deter sick people from seeking treatment.

“You have to treat all who present,” says Quinlan. As for a patient’s citizenship status, “You don’t know and to some degree are restricted in how precise your questions are.”

While hospitals and health centers ask patients for their Social Security numbers, they don’t require a patient to have one and do not ask further questions if they don’t.

Kerrie Jones Clark, executive director of the Rhode Island Health Center Association, said that health centers do not keep tabs on undocumented patients. But in response to the Journal’s inquiry, she looked up how many health center patients lack Social Security numbers. Some patients may have fake numbers or use someone else’s, but the absence of a valid Social Security number is a strong indication that a patient is not in the country legally.

Clark was surprised at how few there were: 4,400 of the 112,000 patients — adults and children — at the 12 community health centers do not have Social Security numbers. A study of how many hospital patients do not have Social Security numbers might indicate how many illegal immigrants are drawing on health care services, but apparently no one has done such an analysis.

Since April 1, the state has required hospitals to use a standardized financial aid form for every person who may be eligible for free care. This new form asks for a Social Security number “if issued.”

The state Department of Health will be collecting data from those forms, and over time, they, too, may provide a glimpse into how many illegal immigrants are using hospitals.

Rhode Island’s Rite Care program provides medical care for poor children up to age 18. But if they don’t meet federal citizenship requirements, the state gets no federal Medicaid reimbursement for their care. John Young, state Medicaid director, estimates there are 3,000 to 4,000 children in that category. But he said he believes most are permanent legal residents who haven’t lived in the country for five years — a requirement to qualify for Medicaid.

Under a new state law, Rite Care stopped accepting undocumented children — whether they are legal residents or not — Jan. 1. Young says he doesn’t know how much that will save the state but believes it is not a large amount.

ILLEGAL IMMIGRANTS are not eligible for state welfare programs, but officials acknowledge that there may be some people with fake papers who are receiving benefits. Some illegal immigrants commit crimes and land in the state prison system.

At the Adult Correctional Institutions in Cranston, it is the federal government that keeps track of immigration violators.

Immigration officials can tap into the prison’s records to determine which new inmates may have violated immigration laws and might be held for possible deportation.

Prison officials hold those inmates on detention warrants — after they have served their time or been freed by a judge — until immigration officials pick them up.

Because state correction officials are required by law to house everyone ordered to prison, the question of their immigration status is irrelevant, says A.T. Wall, state corrections director.

“In the end, it doesn’t matter to us,” says Wall. “We take all comers.”

At the request of The Journal, prison officials took a snapshot of their population one day last month to try to determine how many inmates could be labeled aliens — legal or illegal.

The research showed that of about 3,700 inmates that day, 187 inmates had been designated as foreign-born. Of those, 123 were facing possible deportation, either because they were here illegally or because of the crimes they committed.

Bruce Chadbourne, a Boston-based field officer for the U.S. Immigration and Customs Enforcement, says determining which criminal suspects are here legally is difficult because in the end it is a federal judge who makes that determination.

“I can’t tell you how many illegal aliens there are in Rhode Island anymore than I can tell you how many illegal aliens there are in the country,” says Chadbourne.

Rhode Island is reimbursed by the federal government for some of the expense of housing immigration violators. Once each year, state prison officials send the federal government a list of foreign-born inmates who were held for at least four days during the previous year. In return, the state gets a check each May.

In recent years the payments have ranged from $614,889 in 2004 to an expected check for $1,206,995 for 2007, according to Ellen Evans Alexander, assistant director of administration for the state corrections department.

AS IS THE CASE in other states, no comprehensive state study has been done of the cost of illegal immigration in Rhode Island, says Jeff Neal, Governor Carcieri’s spokesman. “State departments are not required, and in some case are even barred, from asking for that data,” he said.

“You would think that someone would want to know that, wouldn’t you,” says Robert Rector, a researcher at the American Enterprise Institute, a conservative Washington, D.C.-based think tank that takes a dim view of illegal immigration.

Rector says that the costs to state, local and federal governments for poorly educated illegal immigrants mirrors the costs associated with native citizens who are high-school dropouts and work at low-paying jobs. The opposite is true for highly educated immigrants who come here legally, Rector says; they have strong earnings, pay the same tax rates as natives and contribute to the nation’s economic well-being.

“People with Ph.D.s don’t cross the desert in the middle of the night to come across our borders,” says Rector. Using census figures, Rector estimates that an illegal immigrant who is a high-school dropout costs state, local and federal taxpayers $19,500 each for education, health care and other government services.

But illegal immigration tends to benefit some segments of the economy, Rector says, especially businesses seeking cheap labor and wealthy people who pay less for baby-sitters, landscapers and restaurant meals because so many illegal immigrants have entered the U.S. labor market and are willing to work for low wages.

Business leaders do not want burdensome federal or state rules placed on their ability to hire immigrants, says Laurie White, president of the Greater Providence Chamber of Commerce. “We have to understand the important role immigrant labor plays in our economy, not only here in New England but across the country,” says White.

With reports from Journal staff writers Tom Mooney, Felice J. Freyer, Jennifer D. Jordan and Paul Edward Parker.

Tomorrow: The story of one

illegal immigrant’s journey

to Rhode Island.