Officials here want this Boston suburb to become the first city in the United States to systematically track people’s happiness. Like leaders in Britain, France and a few other places, they want to move beyond the traditional measures of success — economic growth — to promote policies that produce more than just material well-being.

Monitoring the citizenry’s happiness has been advocated by prominent psychologists and economists, but not without debate over how to do it and whether happiness is even the right thing for politicians to be promoting. The pursuit of happiness may be an inalienable right, but that is not the same as reporting blissful feelings on a questionnaire.

“Does it matter if I am a little manic right now?” one Somerville resident wrote on the census form. (Apparently not: he gave himself a “10” for happiness.)

So far, more than 7,500 people have mailed back the survey, some of them clearly not limiting their answers to municipal concerns. In response to the question “How satisfied are you with your life in general?” one man gave himself only a 6, explaining, “I would like to be three inches taller and speak Quechua fluently.”

In some ways, Somerville is a perfect test tube for such an experiment. Sandwiched between Harvard and Tufts Universities, the city is a blue-collar bastion with a growing population of young professionals and academics. Somewhat less lovely than its upscale neighbor, Cambridge (but with lower rents), Somerville used to be renowned for crime and nicknamed “Slummerville,” but its reputation and priorities have been changing as it gentrifies.

“We need to change our mind-set in how we serve people,” said Mayor Joseph A. Curtatone, who has been hailed at the White House for the city’s pioneering program against obesity. He called the happiness survey “a no-brainer” that he approved as soon as it was suggested.

“Cities keep careful track of their finances, but a bond rating doesn’t tell us how people feel or why they want to raise a family here or relocate a business here,” Mr. Curtatone said.

To draw up its questions, Somerville turned to a neighbor, Daniel Gilbert, a Harvard psychology professor who wrote the 2006 best seller “Stumbling on Happiness.” Dr. Gilbert, who donated his time, is also helping the city do a more detailed telephone survey, using a randomized sample of Somerville’s 76,000 residents.

“Social policies are always meant to promote things that promote happiness, so how could it be a bad idea to measure directly the very thing you are trying to maximize?” Dr. Gilbert said. “Should we build more parks or highways? Should workers get longer coffee breaks or more vacation days? We don’t have to guess about the answers to these questions.”

Somerville officials say they hope to see how parks and bike paths affect the happiness of people living nearby, or how people’s feelings change when mass transit services are improved.

The survey that was mailed with the census asks people to rate the nuts-and-bolts aspects of their communities — the police, the schools, the availability of affordable housing — as well as the “beauty or physical setting” of Somerville, an industrial town full of triple-decker houses. The city wants to know: “Taking everything into account, how satisfied are you with Somerville as a place to live?”

Then there are the really touchy-feely questions, seemingly plucked from a personality test. “When making decisions, are you more likely to seek advice or decide for yourself?” the survey asks. “In general, how similar are you to other people you know?”

Vanessa Lagerman, 28, who has lived in Somerville for six years, is one resident who appreciates the city’s efforts. “Since I’ve been here, I’ve noticed a lot of things the city has been doing, like installing bike lanes,” said Ms. Lagerman, a graduate student at the University of Massachusetts, Boston. As for the survey, “I think it’s a good thing, because policies can be changed to make people happier.”

Other residents also said they felt flattered by the city’s attention.

“I’m glad they’re trying to use 21st-century tools to get a feel for what people want,” said Conor Brennan, the owner of P J Ryan’s, a pub in Teele Square. “Of course, any survey like this is going to depend on the mood of the person at that moment. If they filled it out in the middle of this last winter, that’s probably going to lower the score.”

Though Mr. Brennan did not recall receiving the form or filling it out, he did offer an off-the-cuff numeric assessment of his own happiness and that of his family: “8+.”

Somerville officials hope to create a well-being index that they can track over time and perhaps eventually compare with results in neighboring towns (assuming the other towns follow their example). But they acknowledge that figuring out how their policies affect that index will be a challenge.

“We want to see what the baseline data tell us and then expand,” said Tara Acker, director of SomerStat, the city’s program to analyze data. “Is there a correlation between happiness and open space or green space? If we see low levels of satisfaction correlated to low levels of income, perhaps we want more programs aimed at low-income people.”

For example, city officials said, the arrival of a new and long-sought extension of the Green Line light rail system to Somerville could be a natural experiment to let them track whether happiness goes up among people who live nearby.

In Britain, a similar happiness survey is being undertaken this spring at the behest of the prime minister, David Cameron, whose administration proposed such drastic spending cuts that violent protests broke out in the street. France, which has had its own riots, has also been analyzing citizens’ happiness.

Fortunately, there has been no such turbulence in Somerville, which prides itself as being the place where Marshmallow Fluff was invented.

“The data may show nothing of interest or they may hold big surprises — you just can’t tell until you collect them,” said Dr. Gilbert, the Harvard professor. “But given that it costs nothing to add some questions about happiness to a census that is already going out, why wouldn’t  you?”