There is power in numbers. The Chinese government knows that only too well. Asian markets got a rare boost yesterday when China released data showing some signs that its economic slowdown might be bottoming out. Its headline output growth figure of 7.7 per cent for the past nine months puts the country on track to meet its full-year 7.5 per cent target. Is that a coincidence or exceptional economic management?

China has more control over its economy than most. Beijing’s tight hold over the banks means it can turn on the tap to finance investment projects when growth stutters. But the opacity of its headline figures gives China added wiggle room. It reports retail sales (up 12 per cent in real terms from a year earlier in the first nine months), fixed asset investment (up 19 per cent) and exports (up 7 per cent). But these data points are just proxies and do not add up to the headline output number. Retail sales for one do not include spending on services such as restaurants. Nor do these data points account for the actual value that shopping and bridge building add to output.

In order to untangle the strands of headline growth, China watchers have to trust other government figures. For example, there is what is called final consumption, an elusive number that is supposed to include services. Ditto, gross fixed capital formation, which supposedly captures the value added by investment. Then there is the added difficulty of revisions to data. China recently revised the contribution of capital formation and consumption to output growth for 2011. As a result, consumption pipped investment as the biggest contributor to output last year for the first time since 2005, according to CLSA data.