London (CNN Business) The global economic slowdown is happening and could spread to the United States next year.

The economies of Germany and Japan shrank in the third quarter, according to data published Wednesday, providing a sharp contrast to another quarter of strong US growth. In China, there are signs of a deepening economic malaise.

The reasons for the weak performance are varied, and economists believe that both Germany and Japan will dodge recessions by returning to growth soon. But the data underscore the major challenges faced by many of the world's largest economies.

Germany's economy shrank for the first time since 2015 in the third quarter. It was hit by new auto emissions testing procedures that slowed car sales and a decline in exports, partly due to the US-China trade war.

The car certification bottleneck is expected to ease, but economists say export growth could weaken further because of reduced demand from major trading partners such as Turkey , Russia and China.

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