Tokyo, officially Tokyo Metropolis, is the capital of Japan and the island nations hub of business, government, education, and mass media. Though Tokyo boasts the largest metropolitan economy in the world, its residents must contend with having the highest cost of living in the world, and one of the most crowded cities more than 5,000 people per square mile. Its also experienced a protracted recession, has an aging population, and is at risk from earthquakes. Despite its problems, Tokyo is one of the planets most important economic centers, with global corporations and exciting modern architecture. Tokyo retains a strong cultural identity, with traditional celebrations taking place throughout the year. City leaders have invested in large-scale plans extending to 2025 to reduce traffic and pollution, and link far-flung neighborhoods with new rail and road-building programs.