Mr. Wörgötter oversaw an O.E.C.D report issued last week that amounted to a warning to German leaders not to get complacent. Though the German economy grew a healthy 3 percent last year, it will grow only 0.6 percent this year and 1.9 percent in 2013, the O.E.C.D. forecast.

On Wednesday, a survey of purchasing managers by the research firm Markit, a closely watched indicator of business sentiment, said that German manufacturing was slowing.

At the end of 2011, the German economy, the world’s fourth-largest, shrank for the first time since 2009. The decline in the fourth quarter of 0.2 percent was not as bad as expected, and growth has probably resumed. Still, most economists do not expect brisk growth to return any time soon.

Germany could add about 10 percent to growth over the next decade if it removed barriers to competition and other inefficiencies, according to the O.E.C.D. Surprisingly, the untapped potential in Germany was almost as high as that in Italy and higher than that in Spain, according to the O.E.C.D., an indication that the German domestic economy is not as superior to its southern neighbors as is often assumed.

Germany’s huge trade surplus, more than 145 billion euros in the first 11 months of 2011, was partly a tribute to exporters like Siemens, Bosch and Daimler. But it also reflected chronically anemic spending by consumers and businesses on imports.

If Germany built up its services sector, it might buy more products from hard-pressed trading partners like Greece or Spain, whose debt problems are closely tied to their longstanding trade deficits. Everybody would win, the argument goes.

Germany would also become less vulnerable to the economic ups and downs of major markets like America and China, said Ulf M. Schneider, chief executive of Fresenius, a German health care company that is the world’s largest provider of dialysis products and services. Mr. Schneider said he worried about Germany’s dependence on the auto industry.