The U.S. Federal Reserve's move to taper off its stimulus program could have an impact on South Korea's housing market, a state-run think tank said Wednesday, calling for the government's stepped-up market monitoring. "Despite continued rise in home prices in the U.S. and China, concerns are still being raised that the Fed's tapering of quantitative easing could result in contraction of the housing market," the Korea Development Institute (KDI) said in a quarterly report that analyzed the latest real estate market situations.