US sees strongest six months of growth in more than a decade The stronger growth was driven by upward revisions to consumer spending and business invesment. Consumption growth is now estimated to have been 2.2pc, up from the initial 1.8pc, while business investment is estimated to have grown by 7.1pc rather than 5.5pc. It was the fourth quarter out of the past five that the economy has expanded above a 3.5pc pace. Data ranging from manufacturing to employment and retail sales suggest the economy retained some of that momentum early in the fourth quarter. The United States remains a bright spot in an increasingly gloomy global economy, with Japan back in recession and growth in the eurozone and China slowing significantly. The brisk economic growth pace could boost expectations the Federal Reserve will start raising its short-term interest rate sometime in mid-2015. The central bank has kept its benchmark lending rate near zero since December 2008. The unexpected strength of third-quarter GDP growth is another reason to expect the Fed to begin normalising interest rates sooner than expected next year. We still anticipate the first rate hike coming in March next year," said Paul Ashworth, chief US economist at Capital Economics.