Higher unemployment and lower stock prices helped send the government's index of leading economic indicators down 0.8 percent in July, the sharpest drop in nine months, the Commerce Department said Tuesday. Analysts had looked for a July decline of about 0.5 percent after an unusually strong 1.4 percent advance in June and a revised 0.7 percent decline in May. The 0.8 percent decline took the index to 192.1 and was the sharpest drop since November, when the index plunged 1 percent, the department said.