If world trade were behaving the way it used to, the global economy would be in crisis rather than just looking a touch wobbly.

During the 1990s and most of the 2000s, goods trade grew at about twice the rate of global gross domestic product. The financial crisis brought with it a massive 12 per cent contraction in trade volumes, which led to a great deal of hand-wringing about a repeat of the collapse in global commerce during the Great Depression. There was then a smart recovery in goods being shipped, which reassured many that business had returned to usual.

In fact, neither catastrophists nor optimists were right. While goods trade has expanded over the past five years, it has done no more than keep pace with the growth of the global economy. Economists and policymakers wondering whether this is a cause for alarm have generally concluded not.