Turkish President Tayyip Erdogan on Thursday renewed his call to parliament to draft a new constitution that will grant his office greater executive powers, arguing it better suits affluent nations."Look at the world. Almost all developed nations either have a presidential system or a half-presidential system," Erdogan said in a speech to local administrators. "Preparations for a new constitution must be bravely carried out (so that) we can present it to the people to decide upon."Erdogan blamed four successive elections for slowing economic growth, increasing unemployment and keeping interest rates high.