China's economy likely grew by 13 percent in the last month of 2009 and market fears that the country is manipulating the data are exaggerated, Jim O'Neill, head of global economic research at Goldman Sachs told CNBC Tuesday.
"Many observers that don't really follow China closely simply don't accept that an economy where the government directs a lot of the big decisions can succeed," O'Neill told "Worldwide Exchange."
"We used to not trust Chinese data ourselves" and this is why Goldman Sachs has computed its own Chinese data for years, he added.
"According to our own proprietary Chinese GDP indicator, in December Chinese growth could have been 13 percent."
The Goldman Sachs China Activity Index shows a strong V-shaped recovery, its growth reaching 13.1 percent year-on-year in December.
The recent reading, together with the latest purchasing managers index reading, "suggests actual (gross domestic product) growth was probably in the 13 percent area towards the end of 2009," O'Neill said in a research note.