Also the IMF certainly could not foresee and take into account the impacts that the terror attacks in Paris and the downing of Russian jet might have on the global economy in its earlier forecast. They will no doubt force the IMF to reconsider its now seemingly upbeat forecast of 3.6 percent global growth for next year.

There is no definitive explanation why the roughly two-to-one ratio between world trade volume growth and world GDP growth has now broken after prevailing for decades. There is also no easy and quick fix to the synchronized slowdown of world trade and global growth which indicates a combination of cyclical and structural factors at work.

It will surely take time for global policymakers to figure out the proper answers to their own countries' underlying economic challenges that require painful structural reforms and policy adaptation in the face of extremely complex economic situation at home and aboard. For instance, in the coming years, all governments need to take seriously the mounting challenge of climate change while preparing for the long-delayed hike in US interest rates that may have unpredictable knock-on effects for developing economies, and thus stoke increased volatility in financial markets, exchange rates and investment flows.

Yet, the onus to fulfill such long-term tasks does not deny the necessity for policymakers to take immediate measures to beef up consumer confidence which is the key to consumption-led growth.

Because consumer spending accounts for more than two-thirds of US economic activity, a stronger-than-expected Black Friday would give a huge boost to the overall confidence in the world's largest economy.

More importantly, the increasing interest of Chinese consumers in participating in the US shopping holiday should galvanize policymakers in both countries to search their toolbox for the means to foster and meet Chinese consumers' growing appetite for a greater choice of goods, which has already been demonstrated in the record online sales generated by China's Singles Day earlier this month.

The author is a senior writer with China Daily. zhuqiwen@chinadaily.com.cn