In 2017, Dr. Mitsuhiro Mimura, Senior Research Fellow at Japan's Economic Research Institute for Northeast Asia, who has visited North Korea 45 times, described it as the "poorest advanced economy in the world", in that while having comparatively low GDP, it had built a sophisticated production environment. He described the recent rise of entrepreneurial groups through "socialist cooperation", where groups of individuals could start small enterprises as cooperative groups. Managers in state-owned industries or farms were also free to sell or trade production beyond state plan targets, providing incentives to increase production. Managers could also find investment for expansion of successful operations, in a process he called "socialist competition". A state plan was still the basis for production, but was more realistic leaving room for excess production.