According to Della Pergola, the Jewish people now comprise .21% of the world's population – whereas they comprised .35% in 1970.
In 1970, there were about 10 million Jews living outside Israel. Only 7.75 million remain. The slight increase in the number of Jews in the world – from 12.65 million in 1970 to nearly 13 million now, is only due to the growth of Jews living in the Jewish state, Della Pergola said.
The demographer said that the only thing that has kept the number of American Jews stable is the hundreds of thousands of Russian Jews that have moved there. He says there is no reason that the size of the Diaspora communities will not continue to shrink.
A previous study done by Hebrew University's Institute of Contemporary Jewry concluded that, barring mass immigration to the Jewish State, by 2030, the majority of the Jewish people will live in Israel due to demographic trends alone. Such a situation would have far-reaching implications according to Jewish law. Click here for an in-depth analysis of the matter.