A closely watched index designed to predict the future health of the U.S. economy posted a third consecutive solid gain in November, a private research organization reported Thursday. The Conference Board said its index of leading economic indicators (LEI)—designed to predict economic activity in the coming three to six months—increased 0.6 percent last month, matching the revised October gain. The index rose 0.8 percent in September after being unchanged in August. "Widespread and persistent gains in the LEI point to strong underlying conditions in the U.S. economic expansion," said Conference Board economist Ataman Ozyildirim. "The current situation ... has been improving steadily, with employment and industrial production making the largest contributions in November." The Conference Board's coincident subindex, which measures current economic conditions, rose 0.4 percent in November, following a 0.2. percent increase the previous month. The lagging subindex, which measures past performance, increased 0.3 percent last month after being flat in October.