There is little question the Postal Service can use help. It supposedly is a self-supporting independent agency, but it is owned by the federal government. Although it pays no taxes, it is not subsidized. It deals with four unions for city carriers, rural carriers, clerks and mail handlers and its labor negotiations are subject to final arbitration.The Postal Service must go through an arduous legislative review each time it wishes to raise a rate or close an office and not surprisingly, few members of Congress will vote to allow any post offices to close in their districts. Moreover, its pension liabilities “would swamp most companies,” Mr. Davis said. So encumbered, the Postal Service lost more than $1 billion in each of the last two years. Although its recent rate increases will probably enable it to turn a profit of $600 million or so in fiscal 2003, which began on Oct. 1, Mr. Nolan puts the amount in context. “That’s enough for two weeks’ payroll,” he said.