Seoul mayor Park Won-soon wants to make the South Korean capital a global role model for the sharing economy, but he’s defending the city fiercely against the very startups that have shaped the concept. Ever since the second-term liberal mayor entered office in 2011, the 60-year-old Park—whose short-lived run in Korea’s presidential race ended last month—has been promoting his “Sharing City” project. The idea is to foster local startups that will ultimately break up economic