WALL STREET heaved a sigh of relief yesterday when the United States Labor Department released statistics on October consumer prices. They rose a modest 0.1 percent, about half the rate many economists anticipated. The day before, fears of inflation had popped up briefly with news of an unexpected jump in wholesale prices for October of 0.7 percent."Yellow flags are flying," Stephen Leeb, editor of Personal Finance, a biweekly newsletter, said Wednesday. Commodity price indexes, he noted, have been rising in recent months. "The inflation numbers suggest that neither inflation nor the US economy are as weak as current media reports are saying." Nonetheless, the long-term trend seems on course, Mr. Leeb said. Global inflation is "under control," and - for the next five years dropping." In the US, the economic recovery continues to be lackluster. The Commerce Department said yesterday that retail sales declined 0.1 percent in October. They totaled a seasonally adjusted $152.9 billion, down from $153 billion in September. Nor has the unemployment rate eased yet. The White House quickly dismissed Wednesday's producer price numbers as an aberration not indicating any long-term trend. The consumer price numbers offered some confirmation. They are up only 2.7 percent since the start of the year. Any sharp jump in inflation would limit the ability of the Federal Reserve Board to further cut interest rates to stimulate the economy. As for the world economy, economists see a relatively smooth road immediately ahead. The pattern for the remainder of the year and going into 1992 is expected to be one of "slow economic growth and general overall stability," says David Hartman, an economist with DRI/McGraw-Hill, an economic consulting firm in Lexington, Mass. There is "virtually no inflation pressure" globally, finds a new study by IDS International Inc. Despite the wholesale price surprise, Mr. Hartman sees inflation generally easing in the US and elsewhere. And DRI predicts that while overall US economic growth will be negative this year, growth will climb into a modest 2 percent range during 1992. Most major economies, including Japan, have slowed considerably during the past year, thus easing inflationary pressures. Except for a few countries such as Italy and, to a lesser extent, Germany, inflation is not considered a significant threat anywhere on the world landscape. Interest rates are heading downward in most countries, reflecting the slow-growth global environment. And cuts in interest rates by central banks in the US and Japan (Japan chopped its benchmark discount rate yesterday from 5.5 percent to 5 percent) have "bolstered optimism" that there will be no major renewal of inflation in those two key nations, according to a recent study by Salomon Brothers Inc. The one major exception, Salomon notes, is Germany, where the Bundesbank has maintained a tight monetary stance. "Germany has succeeded in slowing its economy," says Hartman - a step that became necessary as huge expenditures for rebuilding the formerly communist eastern states brought more inflation. DRI predicts Germany will post a growth rate of around 3.2 percent this year, and about 2.3 percent next year. Consumer inflation continues to be stubborn, by German standards, running at 3.4 percent now, and rising to about 3.8 percent next year, predicts Hartman. In Japan, economic growth is slower than usual. First-quarter growth for 1991 was very strong, around 4.3 percent. But growth is expected to continue to slow - settling into a low 3 percent range for 1992. Consumer inflation, accordingly, is dropping to a manageable 2 percent range. Britain continues to struggle out of recession, although "improvement is under way," says Hartman. DRI projects that Britain will post growth of about 2.7 percent next year. Meantime, inflation continues to come down.