In a twice-yearly report, the bank took a broader look at poverty to see where countries were lagging, even though the share of those living in extreme poverty—defined as earning less than $1.90 a day—has continued to come down in recent years.

Under the expanded criteria for poverty, the report found the number of poor worldwide was still “unacceptably high,” while the fruits of economic growth were “shared unevenly across regions and countries.”

Even though global growth of recent years had been sluggish, the total count of people in poverty declined by more than 68 million people between 2013 and 2015—”a number roughly equivalent to the population of Thailand or the United Kingdom.”

Despite…