BEIJING - China has released a big data blue book on digital development, according to Wednesday's Beijing Daily.

The blue book, also named Report on the Innovative Development of China's Big Data No. 4, focuses on digital innovation, economy, governance, services and security. It constructed a global digital competitiveness index system and evaluated the digital development of cities around the world.

The blue book selected the 15 cities of New York, London, Beijing, Singapore, Shanghai, Sydney, Paris, Dubai, Tokyo, Chicago, Moscow, Toronto, Mexico City, Seoul and Cape Town.

Beijing and Shanghai ranked fifth and eighth in digital competitiveness, while the two cities lead the ranking of digital economy competitiveness.

The blue book was published by the Social Sciences Academic Press.