New Wal-Mart Chief Faces New Challenges

New Wal-Mart Stores Inc. Chief Executive Mike Duke took the helm of the world’s largest retailer Sunday, tasked with keeping his company growing in the midst of a contracting global economy. Mr. Duke, who is only the fourth chief executive officer in Wal-Mart’s nearly 47-year history, succeeds retiring CEO H. Lee Scott Jr. just as the giant discounter has begun to feel the weight of a deepening recession.