Former Federal Reserve chief warns that huge obligations will crowd out needed capital spending.
EU analysis says US GDP would drop 3.4% by 2030.
Growth is expected to slow next year, though, according to BNP Paribas.
Leuthold strategist fears hot economy will push up inflation, threatening advance.
Pantheon’s Ian Shepherdson says tax cuts spurred 4.1% increase, and he thinks future readings will be lower.
Oil-rich nation seeks to diversify its economy and boost its private sector.