State House in Boston, Massachusetts
State House in Boston, MassachusettsiStock

Half of the Jews in Greater Boston do not identify with a Jewish denomination, a significantly higher proportion than the national average, a new study found.

The proportion of Jews not identifying with a denomination also represents an increase since 2005, according to a recently published 2015 study by Brandeis University's Maurice & Marilyn Cohen Center for Modern Jewish Studies and Steinhardt Social Research Institute in collaboration with Combined Jewish Philanthropies.

The number is higher than the 2013 national average, 30 percent, according to a Pew study of American Jews.

The Brandeis and Combined Jewish Philanthropies study found that for those in Greater Boston who do identify with a denomination, Reform is the largest movement, followed by Conservative and Orthodox -- results that mirror the Pew findings.

Greater Boston is home to 248,000 Jews, nearly 7 percent of the city's population, making it the fourth largest Jewish community in the United States, according to the recently published study, for which 5,000 Jews were surveyed.

The number represents a population increase of about 4.6 percent since 2005. The study report noted that the regional population growth was 6 percent but suggested that "much of this growth was driven by Hispanic immigration."

"Therefore, a more appropriate comparison is to the non-Hispanic white population, which decreased by 3 percent from 2005 to 2015," read the report.

The Boston study also found that nearly two out of five households belong to a synagogue and one-fifth are members of a Jewish organization.

Three quarters of children in Jewish households in Greater Boston were being raised exclusively Jewish, with the percentage significantly higher for children of inmarried parents, 94 percent, than those of intermarried parents, 57 percent.

The study described the Greater Boston Jewish community as "affluent and highly educated," but noted that "some segments may be economically vulnerable."