This book contains fifteen original papers covering, a broad spectrum of topics in Jewish demography and identity, considering both Diaspora communities and the population of Israel. While most of the papers make use of quantitative data, some base themselves on qualitative and archive materials. The book is divided into five parts, reflecting the different complementary dimensions investigated: historical demography, history, and politics, immigration and immigrant adaptation, transnationalism, and demography and identity. This work is presented to Professor Sergio Dellapergola upon his retirement from teaching at the Hebrew University of Jerusalem.