The House-Senate Joint Economic Committee called on Taiwan to assess ways to cut its trade surplus to help end world trading imbalances that are threatening the global economy. It said Taiwanese leaders should consider increasing domestic investment and consumption, revaluing their currency upward and further opening home markets to foreign goods. Sen. Paul Sarbanes (D-Md.), committee chairman, said the report was the first in the series of committee studies on world trade imbalances. He said solutions to trade imbalances usually focus on nations with deficits but that those with surpluses, such as Taiwan, also have a role to play. He said Taiwan has only 19 million people but is the fourth largest exporter to the United States.