South Korea's household debt problems are feared to worsen as the Federal Reserve's possible stimulus tapering is likely to spur foreign capital outflows, raising market rates, a report showed Monday. If the U.S. central bank begins to taper its US$85 billion in monthly bond purchases, foreign capital is likely to exit from the Korean market, raising concerns that subsequent rises in market rates would worsen household debt problems, Jeong Young-sik, an economist at the Samsung Economic Research Institute, said in the report.