An estimated 500,000 North Koreans have cash assets worth more than US$100,000, a researcher at the South Korean state-run institute said Friday, indicating a stark gap between rich and poor in the impoverished communist state. In a forum held at the National Assembly, Lee In-ho, senior researcher at the Institute for National Security Strategy, termed those with over $100,000 as the \"rich class\" of North Korea, whose per capita income is estimated at $1,700, compared with South Korea\'s $20,000.