Perhaps you should try some spelling variations:
"world bank chief economists" » "world bank chief economist", "world bank how economists", "world bank women economists", "world bank chinese economists"
"world beck chief economists" » "world beck chief economist", "world beck how economists", "world beck women economists", "world black chief economists", "world best chief economists", "world book chief economists"
"world back chief economists" » "world back chief economist", "world back how economists", "world back women economists", "world black chief economists", "world jack chief economists", "world lack chief economists", "world back china economists"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (("world bank chief economists") OR ((("world beck chief economists") OR ("world back chief economists")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"world bank chief economists\") or (((\"world beck chief economists\") OR (\"world back chief economists\"))))".
• Removing quotes may allow a broader search: (( world bank chief economists ) or ((( world beck chief economists ) OR ( world back chief economists )))).
• Adding a wildcard symbol may retrieve word variants: (("world bank chief economists") or ((("world beck chief economists") OR ("world back chief economists"))))*.