THE HOUSING shortage facing Cambridge has grown to a critical level. Rapidly the city is becoming a middle and upper class area, with workers being forced out because they cannot afford the skyrocketing rents.

There are several reasons for the rising rents in the city. The two mammoth universities bring in more students than they can house and the overflow spills into the city housing market. Since 1960 the number of Harvard students living in Cambridge has risen by nearly one third. Students are generally wealthier than workers in areas like East Cambridge and can afford to pay higher rents. People associated with the universities--secretaries, clerks, faculty, hangers on, etc.--compound the problem.

Expansion of industry in Cambridge has been rapid, especially, university-related industries which employ large numbers of upper and middle class people. The NASA project will soon bring even more of these relatively wealthy professional people into the city. In addition, much of the housing has passed into the hands of speculators who exploit the students and professional people at the expense of the poor and elderly.

Since 1960 rent in Cambridge have doubled. Eight year ago $80 was the median rent for a three-room apartment. Today it is $150. As the shortage grows worse and costs continue to shoot up, lower income residents are forced to leave the city. The effects of the shortage are especially severe for elderly people who live of fixed incomes.

The response of the large institutions and the city government to the plight of the poor has been inadequate. Efforts have been misdirected and poorly coordinated. Last Monday the City Manager announced the formation of a task force to mount a coordinated effort to find low cost housing sites. But even if this effort is a success it will be several year before its effects are felt, and by then it may be too late.

In the interim the most effective answer to the crisis is rent control. The current Rent Control Referendum Campaign Drive makes these proposals:

* Set rents in all apartments except single family dwellings and two an three family buildings back to their January 1, 1968 level and freeze them their for four years.

* Permit rents to be raised 8 per cent per year at the most and then only if the unit meets the health and housing codes. There are three reasons a landlord can give to raise his rent: major capital improvements, a project of less than 6 per cent per year, or an increase in operating expenses or property taxes.

Rent raises would be approved by a seven-man rent board. Five of the board members are to be elected by the citizens of Cambridge and two appointed by the City Council.

Thse proposals offer the best prospect of a rapid improvement in Cambridge's housing situation, and they should be adopted.

THERE ARE admittedly several problems with rent control, especially over the long run. it tends to discourage the building of new housing. Landlords try to advisor making any improvements since they have a difficult time raising rents because of them. These are experiences which cities like New York have has with rent control, and they have laced many people to emphasize the need for low cost housing instead in rent control.

But in Cambridge the City, with Federal help, is the only agency which will build low cost housing anyway, since it is not very profitable, and rent control will not stop the city from building; on the contrary it should encourage more building by forcing speculators out the making more sites available. Further it would free tenants from fear that complaints about building code violations will bring a rent increase, a common practice in the past. The rent control law is a four-year proposal, and if after that period it appears that construction of low cost units has brought the housing situation under control, the law could be allowed to expire.

Most importantly, the rent control drive will mobilize a segment of the community whose interests have been too long ignored. Winning rent control will not be the end of the housing fight. It is obvious that the real answer to the problem lies in the construction of more low rent units, and this must be the next step.

But until that can be accomplished the city must institute a strict rent control law. All registered voters should sign the rent control petition, and all landlords, including Harvard and M.I.T., should act as if rent control were already in effects.