The PRC government regularly revises its GDP figures, often toward the end of the year. Because local governments face political pressure to meet pre-set growth targets, many doubt the accuracy of the statistics.[62] According to Chang-Tai Hsieh, an economist at the University of Chicago Booth School of Business and research associate at the National Bureau of Economic Research, Michael Zheng Song, an economics professor at the Chinese University of Hong Kong, and coauthors, China's economic growth may have been overstated by 1.7 percent each year between 2008 and 2016, meaning that the government may have been overstating the size of the Chinese economy by 12-16 percent in 2016.[63][64]