A Chinese national flag flies in front of a building under construction in the central business district of Beijing, China, on February 1, 2019.

With economic growth slowing down, China needs to increase productivity to boost its economy — but the country hasn't been very successful at doing that so far, according to a report by the World Bank and the Chinese government.

China's economy has long relied on high levels of investments and an expanding labor force for growth. Those economic drivers are running out of steam, and Chinese authorities have identified innovation and productivity as the next growth sources.

But, productivity growth in China "has been slowing since the global financial crisis and has remained relatively low," according to the report, jointly released Tuesday by the World Bank, China's Ministry of Finance and China's Development Research Center of the State Council.

Estimates of China's growth in total factor productivity moderated from about 3.51% in the 10 years before the global financial crisis to 1.55% in the decade post-crisis, the report said. Total factor productivity measures economic efficiency and innovation.

China is not the only country that's facing a slowdown in productivity growth.

However, the sheer size of the Chinese economy — the world's second largest — and its increasing integration with the global economy, means that a growth slowdown in China could have worldwide implications.