Just back from China, renowned economist Jim O'Neill told CNBC on Tuesday that the "incessant focus" on whether the Chinese gross domestic product numbers are accurate and whether GDP there even matters for the rest of the world "seems to be misplaced."
O'Neill—former chairman of Goldman Sachs Asset Management—said he found the Chinese government's growth plan "pretty persuasive," despite predicting the world's second-largest economy is going to "slow even further" while reforms take hold.
In a "Squawk Box" interview, he said the Chinese business owners and senior policymakers he met with during his trip are willing to accept a slowdown in the near term to "improve the quality and long-term sustainability of growth."
"Amongst the things they are moving towards is more freedom of their currency and ... much more flexibility of their own interest rate market," explained O'Neill, who coined the term BRICS—referring to the economies of Brazil, Russia, India, China and South Africa (CNBC Explains BRICS).
In the second quarter, China said its economy expanded 7.5 percent, but that was the ninth slowdown in the past 10 quarters and a dip to the low end of the official government economic growth target for 2013.
(Read more: Forget growth, China is contracting, experts say)
"It baffles me as to why people still persist with this notion of China deliberately fiddling its numbers," O'Neill said. If that's the case, he continued, why wouldn't the government there make sure the "numbers were above or in line" with its forecasts.
He added that Chinese GDP is not the measure most important to the rest of the world, except for commodity producers and heavy industry companies. "If the China GDP slips from 10 to 6 percent, but the consumption rate is staying as strong or strengthening, that's what should be mattering," he said.
"The winners and losers of the new China are very different from the past," O'Neill said. "Caterpillar won't be at the front of the likely winners, nor would many other heavy industry and commodity-related companies."
(Read more: Jim Chanos says mining slump will hurt Caterpillar)
O'Neill stressed that companies focused on "what China is going to consume" should be big winners such as "things that people just buy in shops or health-care and educational things."