According to the Organisation for Economic Co-operation and Development's 2018 "Education at a Glance" report, public spending on higher education in the US is 1.3 percent of GDP. That is equal to public spending in Switzerland and the United Kingdom, and higher than spending rates in Germany (1.2 percent), France (1.2), Canada (1.2), Spain (1), Italy (0.8) and Japan (0.7).

This year, Tsinghua University received a budget of more than 29.7 billion yuan, ranking first among all mainland universities, and up from 26.9 billion yuan last year. Zhejiang University ranked second with 19.1 billion yuan and Peking University third with 19 billion yuan.

Chen Wei, an official at Peking University's Office of Policy and Legislative Affairs, said increased government investment in higher education means universities can hire good teachers globally and have more resources to invest in academic research. This in turn can raise their rankings globally, as academic standing and research impact are important factors in these rankings.

The rise up the rankings is also the result of numerous reforms conducted by universities in teaching and teacher evaluation, he said.

For example, university teachers used to have contracts for life unless they made serious mistakes. However, they now have to be assessed more often, and those that have not made progress academically within a certain period are fired, Chen said, adding that this has prompted teachers to focus more on academic research and an increase in the number of papers published.

According to a statement from QS, the higher education analysts, of the mainland's 42 ranked universities, 32 have improved their performances for its Citations per Faculty indicator.

The country's top 10 universities produced 428,191 research papers in the five-year period used by QS to assess research impact, while the top 10 universities in the US produced 443,996. This means that the output gap narrowed to 15,805 papers, while last year it was 37,233, it said.

Wu Libo, director of Fudan University's planning office, said that according to Essential Science Indicators, a database that surveys more than 11,000 journals worldwide, the university this year published more than 3.7 times the number of papers it produced 10 years ago.

Citations this year were 9.2 times the number for 2009, she said, adding that the university last year published nearly 700 research papers in top journals, including Nature and Science.