How many American Jews are there? A global study of world religions offers a new estimate.

JTA – In its landmark study of American Jewry in 2020, the Pew Research Center reported that there were an estimated 7.5 million Jews of all ages in the United States.

Now, in a new study released on Monday, 9 June, the centre says the number is actually more like 5.7 million.

What happened to 1.8 million American Jews? For the purpose of its latest report, which focuses on global religious population change, Pew is counting only those who self-identify with Judaism as a religion rather than those who identify as Jewish due to “ethnicity, culture, or family background”.

The metric was used because the goal of the project was to “report which religion, if any, people around the world identify with”, according to Conrad Hackett, the senior demographer and associate director of religion research at Pew. In order to generate a number that could be comparable to, say, the number of Presbyterians, researchers needed to use a metric that could apply across communities.

But the metric also means that 1.8 million Americans who identify as Jewish but don’t say they are Jewish by religion are excluded from the tally. The tally also doesn’t detect growth in that population – by Pew’s previous assessment, the fastest-growing segment of American Jews.

The analysis, focused on population change, found that the population of Jews by religion in the US grew by just 30 000 between 2010 and 2020. In contrast, it found that the Jewish population of Israel – as measured by the Israeli government – increased by one million, to 6.8 million, during that time.

In multiple other regions, Africa and Europe, the Jewish population fell substantially, largely reflecting widespread emigration. The European Jewish population fell by an estimated 8%; the Latin America-Caribbean region decreased by 12%; and the sub-Saharan African Jewish population dropped 37%, to just 50 000 in 2020, according to the report.

The overall growth in the world’s Jewish population didn’t increase its proportion of the world’s religious adherents because of the much faster growth in other populations. The study found that Muslims are the fastest-growing religious group, up 21% since 2010, with a total population of two billion.

Various efforts to count the number of Jews in the world have yielded an array of tallies, all below the Jewish population alive before the Holocaust. The Pew report quotes one demographer focused on Jews, Sergio Della Pergola, as noting that Jewish population counts are “permanently provisional” because of both data quality issues and the fact that the question of who is a Jew doesn’t have a fixed answer.