China's policy shifts are a bigger driver of the selloff in emerging markets than the Federal Reserve's decision to dial back stimulus, according to Goldman Sachs Asset Management.

Volatility will rise toward its long-term average, and that means an increase in risk premiums, said Philip Moffitt, head of fixed income in Sydney for Asia and the Pacific at Goldman Sachs Asset Management, which had $991 billion of assets under supervision worldwide as of September. The risks for different emerging economies will become more idiosyncratic and Mexico presents a buying opportunity following the rout, he said.

Markets from Turkey to South Africa and Argentina were roiled during the past month as investors sold off emerging-economy currencies, stocks, and bonds, prompting emergency measures from governments and central banks. The bout of risk aversion follows the Fed's decision to scale back asset purchases and China's pledge to rein in leverage and give market forces a more decisive role in allocating resources.