Our final substantive article treats a philanthropic issue that has been in the news lately. Melissa Berman, Renee Karibi-Whyte and Olga Tarasov (New York), give a detailed treatment of the pros and cons of the traditional ?perpetual' term of private philanthropic trusts and other charities, compared with the newer model of ?time-limited' charities. They draw on the extensive practical experience of Rockefeller Philanthropy Advisors (RPA) working with philanthropies of varying size, types and objectives, as well as from recent mixed-method research surveys undertaken by RPA, which includes a survey of 201 private/family philanthropists from 28 countries and 29 semi-structured interviews with UHNW philanthropists or their senior staff, and a separate survey of 150 philanthropic institutions primarily in the United States and Europe. Their thoughtful conclusion is that the process of deliberating over time horizon possibilities touches on some of the most profound aspects of philanthropy: legacy, family, and the size and urgency of the world's problems. For this reason, wealth advisers and family office executives should approach the issue delicately and diligently. This article provides a unique guide.