LOS ANGELES — A U.S. economic index based on diesel fuel purchases showed some modest improvement after several consecutive months of decline.

The Ceridian-UCLA Pulse of Commerce Index bounced back a bit last month to 0.4 percent after declining 0.6 percent in October.

Overall, though, the index has dropped 2.1 percent since July, suggesting continued weakness within the goods producing segments.

"In short, November’s ‘up’ is relative to a low-bar so the growth is only mildly encouraging," explained Ed Leamer, chief PCI economist and director of the UCLA Anderson Forecast. "The flatness we’re seeing with the latest PCI data reflects inventories in motion which seem to be signaling a weak fourth quarter."

The growth rate, researchers say, is below levels needed for rapid recovery to the previous peak in 2007-2008.

"There has been less anxiety about the economy in recent months, but markets are still fragile," said Craig Manson, senior vice president and index expert for Ceridian. "We still have not seen evidence of enough growth to instill confidence in the economic outlook for the fourth quarter and early 2011."