Question: I received mail claiming to be from the U.S. Census Bureau, American Community Survey. I want to know if this is legitimate, and not a scam. If it is legitimate, is it required by law that I send this in?

Answer: Based on the contact information you provided Kokua Line from the mail you received, it appears the Census Bureau has indeed randomly selected your address to participate in the American Community Survey, the detailed annual data collection that replaced the old long-form decennial census. Information from the ACS helps determine how more than $400 billion in federal and state funding is distributed throughout the country each year.

You were wise to verify the authenticity of the survey, given that scam artists spoof the Census Bureau and other government agencies in their criminal efforts to extract valuable information from unwitting victims. We are confident this mailing is valid because it contains the Census Bureau’s correct toll-free telephone number, 800-354-7271, and the return address matches the bureau’s national processing center, P.O. Box 5240, Jeffersonville, IN, 47199-5240.

You may call the toll-free number and provide the code on the ACS form you received to verify this information.

About 3.5 million U.S. addresses are selected annually to participate in the ACS, which includes questions about age, race, disability status, housing, occupation, military status, living expenses and other topics. The collective responses influence local, state and national funding and policy about everything from where to build preschools to how to help elderly people age in place. Individual answers are strictly confidential, the Census Bureau emphasizes.

The forms are mailed to addresses, not named individuals. Moreover, the ACS never asks for your Social Security number, your personal information via email, credit card information, money or donations. Anyone who receives mail purporting to be the ACS that seeks such information can be sure it’s a scam.

As to your second question, the Census Bureau asserts, and the U.S. Government Accountability Office affirms, that federal law obligates people who receive the ACS to answer all the questions as accurately as they can. The Census Bureau cites Title 18 U.S.C. Section 3571 and Section 3559, which amends Title 13 U.S.C. Section 221, as authorizing this “legitimate, mandatory” questionnaire. Individuals can be fined as much as $5,000 for refusing to answer, and up to $500 for willfully giving wrong answers, according to the U.S. code cited.

However, these penalties are rarely if ever enforced, which is why the Texas edition of the fact-checking website Politifact gave the Census Bureau’s warning that “federal law requires residents to participate in the U.S. government’s American Community Survey” only a “mostly true” rating in 2014.

The essentially unenforced mandate reflects the reality that the Census Bureau does not want to penalize people into complying, and prefers that they agree to participate because they realize that doing so can help their communities, according to the Politifact analysis.

Q: What happens if I ignore the census survey that was mailed to my house?

A: You will hear from the Census Bureau again, definitely by mail and perhaps by telephone or even in person. The bureau explains on its website that it uses a “multipart strategy” to collect American Community Survey responses. Once randomly selected, addresses cannot be removed from the sample, it says.

Here’s how the process works, according to the website: First, you receive a letter informing you that your address has been selected for the ACS. Then, you’ll most likely receive instructions about how to complete the ACS online. If the survey is not completed, the bureau follows up about two weeks later by sending out a replacement questionnaire. If you still don’t respond, the Census Bureau may call you. If the bureau cannot reach you by phone, it may send out an interviewer to your home address. The staffer may arrive after regular business hours, including evenings and weekends, when it is more likely you will be home.

All this outreach would add significantly to the cost of collecting the socioeconomic data, obviously.

For more information, see census.gov/programs-surveys/acs. The site includes ways to confirm that any contact you receive, whether by mail, telephone or in person, is legitimate.

Write to “Kokua Line” at Honolulu Star-Advertiser, 7 Waterfront Plaza, Suite 210, 500 Ala Moana Blvd., Honolulu 96813; fax 529-4750; or email kokualine@staradvertiser.com.