Wanderlust World Wanderlust World According to World Bank data from 2020, China's population stood at approximately 1.4 billion, while Japan's was about 126 million. This results in a staggering difference of roughly 1.27 billion people. China remains the world's most populous nation (recently surpassed by India), while Japan faces a declining, aging population. The gap reflects vastly different demographic trajectories, with implications for labor markets, social systems, and economic policy in both countries.