The possibility of the euro becoming the first international reserve currency has been debated among economists. Former Federal Reserve Chairman Alan Greenspan gave his opinion in September 2007 that it was "absolutely conceivable that the euro will replace the US dollar as reserve currency, or will be traded as an equally important reserve currency". In contrast to Greenspan's 2007 assessment, the euro's increase in the share of the worldwide currency reserve basket has slowed considerably since 2007 and since the beginning of the worldwide credit crunch related recession and European sovereign-debt crisis.