Along with the impact of Britain's recent vote to pull out of the European Union, the continuing slowdown in China's economy remains a major source of concern for global growth and clouds prospects for the Japanese economy. As host of the Group of 20 meeting of finance ministers and central bankers in Chengdu over this weekend, where international responses to decelerating growth of economies worldwide will be among the key agenda, the Chinese government needs to do more to put its own economic act together.

China said last week that its gross domestic product for the April-June period rose 6.7 percent in real terms from a year ago — the same rate of growth as in the January-March quarter, when the pace was the slowest since the 6.2 percent growth in the first quarter of 2009 — right after the Lehman shock in the previous fall. On the face of it, China's growth falls within the government's 2016 target of a 6.5 to 7 percent increase. But the fact that GDP growth remained at that level despite the increased fiscal spending such as infrastructure investments to prop up demand seems to point to the continuing fragility of growth in the world's second-largest economy.

And as is always the case, the credibility of these official figures is in doubt. Fluctuations in GDP growth across quarters generally fall within a zero to 0.2 percentage point range. It is now widely believed that the GDP data is being manipulated by Chinese authorities to keep the rate within the official target — and that China's growth is indeed much slower than the statistics suggest. The latest figures do not warrant any optimism about China's economic prospects.