Concerns follow good economic signs

This time a year ago, the world economy seemed to be getting on a better plane. A number of cyclical indicators suggested the world economy would grow about 4 percent in the latter half of 2017, raising hopes that it would allow a multi-year end to the decade of 4 percent growth. These indicators included the Republic of Korea's exports, the first country to report trade every month, which for the whole year reported the fastest rise it has ever had in exports.

Many countries were reporting accelerating monthly business confidence surveys, as shown for example, by the Purchasing Managers Index, while some particularly troubled economies from earlier in the decade, such as the eurozone, were showing especially encouraging signs. And at its annual meeting last year, the International Monetary Fund revised up its world GDP estimate, something that continued in its spring meeting this year.

A familiar trend makes come back