from The Jewish Week:

N.Y. Population Study Inflated, Says Top Demographer

One of the world’s leading Jewish demographers says the number of Jews in New York is really about 100,000 less than indicated by the new Jewish Community Study of New York, commissioned by UJA-Federation.

[Sergio] Della Pergola [professor of population studies at the Hebrew University] said the issue was significant because by his criteria, the Jewish community has not grown in the last 20 years but rather “has remained stable.”

Steven M. Cohen, a demographer who helped conduct the survey, said the number of people Della Pergola is referring to is closer to 19,000, or about 1.2 percent.

Jack Ukeles, head of Ukeles Associates, which helped conduct the new study, said that he and his fellow researchers interviewed a number of people who said they were partially Jewish, and others who first identified themselves as Jewish and in the course of the interview said they belonged to another religion. The “vast majority” of these people, Ukeles said, were children of intermarriages.