Jerome Booth, head of research at $33 billion-in-assets Ashmore Investment Management in London, was having lunch in Munich last month with a large German institutional investor who was crowing about changes he had made to his portfolio. After years of hearing Booth preach about the need to dramatically increase exposure to emerging-markets economies, the investor excitedly announced that he had shifted his conservative stance and doubled his allocation — to 10 percent. Unimpressed, Booth deadpanned, “So you’re still comfortable with 90 percent in the crash zone?”