An assistant to the state census director said yesterday that a 15 per cent drop in the Cambridge population, shown in the 1971 state census, is due mainly to the irresponsibility of the census takers.
He said that many of the census takers "merely took the town directories and copied them down."
Cambridge population figures from the January 1971 census are about 15,000 lower than those reported by Federal census takers eight months earlier.
The assistant, William Lewis, said that the wide discrepancies between the two surveys are largely due to the irresponsibility of each individual town in checking up on its census takers.
He said that many of the towns did not follow the directions which the census bureau gave them.
Last month the Democratic City Committee of Cambridge voted to authorize a lawsuit attempting to enjoin state officials from using the 1971 state figures as a basis of reapportionment of state funds or representatives.
If the state census is used for the reapportionment as currently planned, Cambridge could lose as much as $100,000 per year in state funds and one of its five representatives to the State House of Representatives.
John Brode '52, chairman of the Democratic City Committee, said that the original figure for the state census of Cambridge was 29,000 lower than the Federal figure because Cambridge didn't count students.
"They submitted a new total by adding the student enrollment lists to the figure of 72,000," Brode said. However, he said that many of the students on the rolls were no longer in Cambridge.
One precinct in Cambridge had 1877 inhabitants according to Federal figures, but only 823 by the state tally. Brode said that in 1972 the number of registered voters exceeded the state census total.
Lewis said that most of the cities and towns in the state showed wide variations between the two surveys. He said that in Lowell, for instance, the census takers didn't count anyone under 17, so the figures were completely wrong.
The largest discrepancy showed in the town of Harvard, which has a high military population. The Federal census showed a population of 13,000 in the town, while the state figures were about 3000 -- a difference of about 75 per cent.
Harvard town officials did not count many of the military personnel stationed there.
Brode said yesterday that Cambridge census takers had not counted many young people who live in apartments in the city because they thought they were students.
"However, many of them are not students, so they didn't get counted at all," he added.
Presently all reapportionment of state lottery and other funds, as well as for representatives, is done according to the state census figures. If the Cambridge lawsuit is upheld, a new census will be taken before any reapportionment takes place.
Brode said yesterday that the hearings for the lawsuit should begin later this month.