Even if times ahead are troubled, the long run is likely to look much more settled. In the short run, a housing slump could well make private investors and central banks outside the U.S. less eager to hold dollars. A survey by the U.S. Treasury Department last year indicates that about third foreign-held U.S. corporate debt consisted by asset-backed securities and about half of that was mortgage-related. Petro-dollars held in the Middle East and Russia are particularly mobile. Once foreign money leaves the U.S., the dollar would fall. In the longer run, U.S. exports would rise, shrinking the huge U.S. trade deficit. Moreover, recession in the U.S. would lead to lower imports, further reducing the trade deficit. At the same time, China may well let the yuan rise against the dollar, leading to a rise in its domestic spending relative to its exports. Once U.S. consumers spend less and Chinese consumers spend more, the large global imbalances, which have cast a shadow on the world economy for the past decade, would begin to disappear.
basic magnitudes ... where is the problem?