Jack is back at Twitter, FT readers on the global economy, and more Martin Wolf

Media correspondent Shannon Bond asks San Francisco correspondent Hannah Kuchler and management editor Andrew Hill what Jack Dorsey's dual CEO roles at the messaging company and payments group Square mean for both companies' future. Producer Aimee Keane reports from the annual #FTPubQuiz in New York. Finally, Cardiff Garcia previews one more excerpt from his long-form Alphachatterbox interview with chief economics commentator Martin Wolf.