The number of cases heard by the U.S. Supreme Court is declining in part because of the lack of significant legislation coming out of Congress, Chief Justice John Roberts said at the Alaska Bar Association’s annual convention.

“No one actually knows why the number of cases we are taking is declining,” Roberts said Thursday as the keynote speaker at the association’s banquet. “I think there really are three significant reasons. The first is the lack of any major legislation coming out of Congress in the last couple of decades.”