The Federal Reserve could begin easing by March, he said.
The firm's strategists don't see the Fed starting to cut rates until 2024.
World Bank Chief Economist Carmen Reinhart said the situation is turning into a "major economic crisis."
A tit-for-tat trade war between the U.S. and China may spill over into a global economic downturn.
In particular, the ballooning deficit and related lending risks trouble the prominent economist.