WASHINGTON, April 15 Reuters U.S. economic growth that keeps motoring above its potential is emerging as a key prop for an ongoing global expansion, but spillovers from persistently high inflation and tight monetary policy in the world39;s largest economy could pose new risks to a hopedfor soft landing around the world.

As global financial leaders gather in Washington this week for the spring meetings of the International Monetary Fund and World Bank, the outlook for the world39;s shortterm economic fortunes may center on whether the surprising U.S. success is being driven more by constructive forces like increased labor supply and productivity or by outsized fiscal deficits that continue stoking demand and, potentially, inflation.

One answer supports what Chicago Federal Reserve President Austan Goolsbee has labeled a golden path where strong growth and falling inflation coexist, not only in the U.S. but in other countries tied to it through exchange rates and trade channels that have kept imports near record highs. The other may point to a bumpy ride ahead if the Fed concludes that U.S. demand remains too strong for inflation to fall, and decides it has to postpone expected interest rate cuts or in the extreme resort to rate hikes it had all but taken off the table.

Recent data have not been helpful, with inflation stalled well above the U.S. central bank39;s 2 target for the first quarter of the year, gross domestic product still expanding above potential at 2.4…