This week is a moment of truth for Xi Jinping on deflation

When US President Donald Trump

stands before a joint session of America’s Congress

on March 4, no one knows what he will say. Policymaking in the world’s biggest economy has become unpredictable, a swirl of executive orders, social media posts and congressional wrangling.

In recent days, for example, Mr Trump has taken to social media to announce

a new 10 per cent tariff on China

, on top of a similar levy imposed in February, causing Chinese stocks in Hong Kong to fall by over 3 per cent on Feb 28. He has also urged Congress to pass a stopgap spending Bill to avoid an imminent government shutdown.