News that Israel’s Central Bureau of Statistics (CBS) is rethinking its approach to counting diaspora Jewry is a welcome development. The CBS has consistently undercounted world Jewry, particularly the Jews of the United States who are the largest diaspora Jewish community. At a time when antisemitism and anti-Israel sentiment are increasing, ensuring that Israel understands the size and composition of the worldwide Jewish community is of enormous strategic importance.

In countries where Jews are a minority population, it is challenging to collect accurate population data. In the United States, the Census Bureau is prohibited from asking questions about religion, and its questions about ethnicity do not identify those who are Jewish. Official government statistics notwithstanding, increasingly sophisticated surveys, sponsored by public policy institutes as well as Jewish communal organizations, enable estimates of the American Jewish population.

There is a growing consensus about the size of the U.S. Jewish population among scholars of the American Jewish community. Multiple studies, including a recent survey conducted by the Pew Research Center, as well as a synthesis of data from hundreds of studies conducted by the American Jewish Population Project at Brandeis University, indicate that the U.S. Jewish population now exceeds 7.5 million adults and children.

Current estimates of the U.S. Jewish population represent a 35% increase in the number of U.S. Jews from 1990 and a 10% increase over the last decade. The estimate does not include the nearly 3 million adults who have Jewish parentage but do not consider themselves Jewish, nor does it include children in Jewish households who are not being raised Jewish in some way. Even as a conservative estimate, the 7.5 million figure contrasts significantly with the estimate of 6 million U.S. Jews currently used by the CBS.

Skeptics may believe that the consensus estimate of 7.5 million is the result of a change in the definition of “Who is a Jew.” However, current studies use essentially the same sociological definition that has been relied on by researchers for decades. An adult Jew is an individual who considers themselves to be Jewish and has Jewish parentage or has converted. A Jewish child is someone under the age 18 who lives in a Jewish household and is being raised in some way Jewish.

What has changed is that an American Jew is increasingly likely to marry or partner with a non-Jew.  However, in contrast to patterns of earlier generations, the children of intermarried parents are increasingly likely to be raised Jewishly, receive Jewish education and, as adults, claim their Jewish identity.

Professor Sergio DellaPergola of Hebrew University, who has long studied Jewish population dynamics, is the progenitor of the CBS’ current estimate. His population estimates include only those in the Jewish population whom he considers “core Jews.” In particular, he excludes adults who are the offspring of only one Jewish parent and who indicate they are Jewish because of ethnicity, culture or family connection, but who otherwise claim no religion. Notably, he excludes some who are halachically Jewish (i.e., a Jewish mother and non-Jewish father).

There are profound implications to excluding some Jews who have only one Jewish parent. To the extent the decision is based on whether they think of their Jewish identity as religious or secular, it establishes a criterion for Jewishness that is not applied to other Jews. Given the important role the United States Jewish community plays vis-à-vis Israel, it does not make sense to reject some Jews. It creates unnecessary divisiveness and undermines efforts to build bridges among world Jewry.

Some may argue that population counts are not meaningful. Nevertheless, knowing the size of the population provides the denominator that makes it possible to understand the ways and extent to which different communities, and groups within the community, express their Jewish identities and their relationship with Israel.

Knowing the size of the population provides the denominator that makes it possible to understand the ways and extent to which different communities, and groups within the community, express their Jewish identities and their relationship with Israel.

One measure of U.S. Jewish identity has traditionally been connection to Israel. Even when one includes the U.S. Jews currently ignored by Israel’s official statistics, the vast majority of American Jews feel an emotional connection to Israel, and nearly half of them have visited Israel. Those U.S. Jews who have spent time in Israel tend to be the most highly attached and supportive of Israel. Many of these individuals have a long history of Jewish education and involvement; however, we also know that the educational efforts can have a significant impact on the Jewish trajectories of less connected Jewish adults.

Birthright Israel, for example, has brought nearly half of million North American Jews to Israel since 1999. One third of the participants are children of intermarried parents, and many of these individuals would not have been counted as Jews by the CBS. Two decades of research demonstrates that participation in Birthright produces long-lasting effects on these individuals’ connection to Judaism and to Israel. Participation has an especially strong impact on those from one-Jewish-parent households and those whose only connection to Judaism is non-religious.

To be Jewish is to be connected to Jews in the past, present and future. Especially in a crisis-torn world, it makes no sense for the Jewish population estimates used by the government of Israel to exclude some Jews based on how they express their Jewish identities. Our collective future depends on understanding our strength and appreciating the diversity of our respective communities.

Leonard Saxe, PhD is the Klutznick Professor of Contemporary Jewish Studies and Social Policy at Brandeis University