LESTSCHINSKY, JACOB (1876–1966), Russian-born pioneer in sociology, economics, and demography of Jewish life. Lestschinsky, who was born in Horodicz in the Ukraine, was deeply affected by *Aḥad Ha-Am and became a member of the *Benei Moshe League when he was 17. He and his brother Joseph established a modern Hebrew school in Horodicz which became famous for its tutelage. He studied at Berne and Zurich universities, pamphleteered for Zionist Socialism, principally in Warsaw, and served as a Zionist delegate at the Sixth Zionist Congress in Basle, where he supported the territorialists. He helped found the Zionist-Socialist (S.S.) Party, writing for it and for other journals on economics under the name Ahad ha-Kanna'im. "Statistics of a Small Town" (1903) was his first study in the field he was to concentrate on, and was followed by two applications of Marxist methods, Der Yidisher Arbeter in London (1906) and Der Yidisher Arbeter in Rusland (1906). After 1906 he was not active in party politics, although he remained a Zionist activist. At this period he published two series of studies on conversions in different countries (1911) and on German Jewry (1912). Before 1914 he operated an ort employment agency for Jewish refugees in Warsaw. During the February Revolution in Russia he helped found the United Jewish Socialist Party and served on the editorial board of Naye Tsayt, its official journal.
In 1921 Lestschinsky left Russia and established himself in Berlin, where he was the Forward correspondent, a connection he maintained virtually until his death. His Yidishe Folk in Tsifern (1922) viewed Jewish demography in worldwide perspective. Early in the 1920s he helped establish the Institute for Research into Contemporary Jewry and Judaism. He served as editor of an important journal, Bleter far Yidishe Demografie un Statistik, from 1923 to 1925. His Probleme der Bevoelkerungs-Bewegung bei den Juden (1926) has been called "one of the most brilliant investigations of problems of Jewish demography ever published." His study Die Umsiedlung und Umschichtung des juedischen Volkes im Laufe des letzten Jahrhunderts (1929–30) was of fundamental importance. In the 1920s he directed *yivo's economics and statistics section, and his work appeared in yivo publications. Less than two months after Hitler came to power in Germany, Lestschinsky sent a dispatch to Forward which was published in the New York Times on March 26, 1933; in it he said: "The Hitler regime flames up with anger because it has been compelled through fear of public foreign opinion to forego a mass slaughter of Jews. It threatens, however, to execute pogroms if Jews in other countries make too much fuss about the pogroms it has hitherto indulged in." Arrested by the Nazis upon publication of the dispatch, he was expelled from Germany. In 1934 he went to Warsaw, but was expelled from there in 1937 for publishing material on the plight of the Jews in Poland. In 1938 he went to the United States. During the war he lived in New York, and worked with the Institute of Jewish Affairs of the World Jewish Congress. One of the earliest students of the Holocaust, he wrote two basic studies in this field, Di Yidishe Katastrofe (1944) and Crisis, Catastrophe, and Survival: A Jewish Balance Sheet, 1914–1948 (1948). In 1959 he moved to Tel Aviv, and in 1964 to Jerusalem, where he remained until he died. His collection of books and papers, which he somehow maintained throughout his wanderings, are at the Institute of Contemporary Jewry of the Hebrew University.
P. Glikson, in: jjso, 9 (1967), 48–57, incl. bibl.; J. Anilowicz, in: yivo-Bleter, 10 (1936), 327–39, a bibl.; A. Manor, Ya'akov Lestschinsky (Heb., 1961); idem, in: jjso, 4 (1962), 101–6.