The housing "emergency" in Cambridge over the past 12 years has affected people of various economic classes. A successful college professor recently said that one of the major reasons he turned down an offer of tenure at Harvard was his fear of searching for housing in the area.

But it's surely not college professors who are hurt the most. The rising competition for Cambridge housing has priced low-income people out of the private market and prompted an increasing number of applications for public housing. City officials say that despite stepped up efforts, they still have not been able to reduce the amount of people who need public housing but are unable to find available space.

There are currently 2,200 families on the waiting list of the Cambridge Housing Authority (CHA), which manages public housing in the city. Officials say that although the names continue to change, the amount is about the same as when the current CHA administration took over five years ago.

The rapid pace of ongoing private development within Cambridge has helped the general economy, but it has also swallowed large tracts of the city's land, making the construction of any significant amounts of new public housing virtually impossible. "We're running out of space in this city for poor people," says Cambridge Mayor Alfred E. Vellucci, who himself lived in Cambridge public housing during the 1950s.

City, state and federal officials say that rising demand and spiraling maintenance costs have outpaced public funding. "The public effort has been strong, but whether it has been enough--that's the question," says Charles MacSweeney, information director for the state Department of Communities and Development.

Frederick Putnam, director of development for the CHA, says his agency is concentrating on the renovation of both its existing stock and of other units which it may acquire. "We re getting an unusually high level of funding for renovation and design." Putnam said.

The major projects currently underway are the complete renovation of the Washington Elms housing project in central Cambridge and the Jefferson Park units available upon completion.

The CHA also recently completed renovations on the Roosevelt Towers project in East Cambridge and the River Howard project in Riverside.

Approximately 10,000 people live in the 3,000 units directly owned and managed by the CHA. Putnam said. The CHA also subsidizes rents in an additional 800 units in privately owned buildings.

The federal government supplies 65 percent of the CHA's funding, with the state adding the remaining 35 percent. Both state and federal laws impose eligibility guidelines on the CHA.

For example, the maximum annual income for a family of four in public housing is $17,400. Putnam said his agency must accept applications from people currently living outside of Cambridge, but that Cantabrigians are given preference.

Peter Quinn, manager of the Newton Court project, said most residents of his apartment have spent "easily one, two, or more" years on the waiting list before gaining entrance into the program. He said the majority have moved to public housing from privately-owned units with skyrocketing rents.

Putnam says the CHA is looking to acquire additional housing units. He says prices for housing "in the ring around Harvard" are too high, but in areas where public housing already exists--primarily North and East Cambridge--there are still affordable units.

"We're looking-at smaller sites for a limited number of family units." Putnam says. "That's where the greatest shortage lies."