In 2010, a World Bank economist denied that China's GDP figures were politically manipulated:
Is the data manipulated by the authorities to meet political objectives? My answer to it, at least regarding the data in recent years, is a firm NO. How do I know that? The reason is pretty simple: in such a big economy as China, it is extremely hard, if not impossible at all, to massage the data without leaving any trace—any manipulation in the data will be quickly spotted by observers—and I personally haven’t found any signs of data manipulation in recent years.
As a consumer of a wide range of Chinese statistics, I carry out exercises like what is shown above fairly frequently. I personally haven’t found any significant inconsistency in Chinese data over the last decade. It makes me believe that data manipulation is not a big problem in China in recent years. Indeed, this is the consensus in the academic field as most researchers on this topic agree that there is little sign that China is manipulating its economic data.
However, this 2019 SOuth China Morning Post article reports on one of a series of cases of manipulation identified by the Chinese National Bureau of Statistics
Officials in the central Chinese city of Guanghan have been found to have gone to extraordinary lengths to manipulate raw data to obscure the real picture of the health of the economy, according to the National Bureau of Statistics, in the latest case to undermine the accuracy of economic data in the mainland.
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In particular, under pressure from the local government, industrial firms falsified detailed data on business revenues, depreciation of fixed assets, payroll, and operating profits.
In 2020, Heritage.org reported on a Federal Reserve Bank report on the unreliability of China's GDP figures
How China sets its overall budget, the actual size of its military budget, the relationship among various political factions, and even how specific decisions may be staffed are all elements that the [People’s Republic of China] deliberately strives to conceal. Nonetheless, as the world’s second-largest economy, as a permanent member of the U.N. Security Council, and as a major power, the PRC has to provide some information about its economy, its political positions, and its various national and international endeavors, if only to interact with other states and economies.
Is it safe to rely on GDP figures coming from China economically?