Treasury Secretary Henry Paulson today delivered his first public address since he was sworn in three weeks ago to an audience of faculty, students and friends of the School in Low Library.Paulson said the U.S. economy is in a “position of strength” but cautioned that four long-term challenges must be addressed: overhauling Social Security, Medicare and Medicaid to fight rising costs; increasing energy security; strengthening open trade policies; and combating issues of uneven wage distribution and growth.Paulson also affirmed his support for a strong U.S. dollar. “I believe that a strong dollar is in our nation’s interest and that currency values should be determined in open and competitive markets in response to underlying economic fundamentals,” he said.He said the economy was in the process of slowing to a more sustainable rate of growth and championed the role of open markets in supporting further expansion.“I will be a strong advocate for free trade and will encourage other countries to open their markets to American goods, services and capital,” he said. “The world is a competitive place. And if we are to retain our competitive advantage, we need to welcome competition and not run away from it.”Remarking on “antitrade rhetoric” he has heard at home and abroad, and on his own career advising clients in international markets, Paulson said, “If this experience has taught me anything, it is that nations that reform their economies and open themselves to trade and competition benefit their own citizens greatly. They see more jobs and higher living standards. And those nations that don’t take these steps are left behind.”Before coming to the Treasury Department, Paulson was chairman and CEO of Goldman Sachs. He joined the investment banking firm in 1974.Paulson said he would take a bipartisan approach to working with Congress. Though many in Washington have already warned him that reforming Social Security verges on the impossible, he is not shying away from the challenge, he said.“I have always tried to live by the philosophy that when there is a big problem that needs fixing, you should run toward it rather than away from it,” he said.