China’s top statistician has acknowledged the country’s problems with falsification of economic data, pledging severe punishment for perpetrators in a nod to widespread suspicion that official numbers often fail to reflect true economic conditions.

“Currently, some local statistics are falsified, and fraud and deception happen from time to time, in violation of statistics laws and regulations,” Ning Jizhe, director of the National Bureau of Statistics, wrote in a column for Communist party mouthpiece the People’s Daily on Thursday. 

Foreign economists and investors have long expressed doubts about China’s economic data. Most prominent are concerns about gross domestic product figures. Compared with other countries. China’s inflation-adjusted GDP growth rates are remarkably stable from quarter to quarter, even as nominal figures show considerable volatility. The NBS has denied charges that it manipulates inflation data to massage headline growth figures.