The author answers four questions about American Jewish demography: How many Jews live in the United States? Is the number increasing or decreasing? Do more Jews live in Israel or in the United States? And do the answers to these questions matter? The author contends that the controversy surrounding these issues stems from the existence of various definitions of Jewish identity as well as the methodological difficulties involved in estimating Jewish populations. He argues that whether the American Jewish population is increasing, decreasing, or remaining the same is not totally clear, though it will almost certainly decrease in the future. The author concludes that the number of Jews in the United States is higher than the number in Israel, yet this is also likely to change in the future.