FED-master675Sounding a somber note even as the economic outlook in the United States brightens, the Federal Reserve’s No. 2 official acknowledged on Monday that global growth had been “disappointing” and warned of fundamental headwinds that might temper future gains. The official, Stanley Fischer, who took over as vice chairman of the Fed in June, noted that although the weak recovery might simply be fallout from the financial crisis and the recession, “it is also possible that the underperformance reflects a more structural, longer-term shift in the global economy.” In a speech delivered on Monday in Stockholm at a conference organized by the Swedish Ministry of Finance, Mr. Fischer also conceded that economists and policy makers had been repeatedly disappointed as the expected level of growth failed to materialize. More