Dr. Nathaniel H. Leff was a professor of Economics at Columbia University Business School for over twenty-five years. Among his published books are two volumes on "Underdevelopment and Development in Brazil" which is being translated in Portuguese and taught in Brazilian Universities. A reporter for a Brazilian newspaper wrote a fascinating article about Dr. Leff's academic influence. Here is a summary of Dr. Nathaniel Leff's academic career: https://prabook.com/web/nathaniel.leff/953812
For years, Nosson Chayim Leff wrote a weekly "email on the Sfas Emes" (available here), and finally wrote a sefer, Emes Ve'emunah, A Sfas Emes Companion, published by Menucha publishers.
Dr. Leff and Nosson Chayim Leff were the same person.
He had a very positive influence on many people through his multi-faceted personality. We are looking for stories from people who interacted with Dr. Leff, to share within the family or to post on this website.
The family held an אזכרה and siyum on Shas Mishnayos to mark the end of the Shloshim (30-day) mourning period for Dr. Nosson Chayim Leff z”l took place on February 7th, ג׳ אדר א׳ at Khal Tiferes Boruch (Rabbi Weinberger’s shul), where Dr. Leff used to daven in Passaic, New Jersey. The speeches were recorded.