INTEREST RATE DIFFERENTIALS TOO SMALL, BANKER SAYS
  Swiss National Bank President Pierre
  Languetin said a wider interest rate differential between the
  dollar and stronger currencies was needed to brake the dollar's
  fall.
      At a news conference, he said Japan and West Germany could
  try to stimulate their economies further by expanding money
  supply, but he added "I'm not so sure it would be desirable if
  monetary policy became more expansive.
      "But what would be useful is a greater differential in
  interest rates," he said.
  

