The political stalemate in the U.S. may spur a fresh round of quantitative easing from central banks around the globe, Morgan Stanley said.
Many global policy makers likely now have a "strong impression" that the world remains risky, especially given uncertainty over the U.S. budget policy in the near term and structural challenges in emerging markets in the medium and longer term, said Joachim Fels, chief international economist at Morgan Stanley, in a note after the IMF/World Bank annual meeting in Washington, DC.
"This, together with the advent of a Yellen Fed that remains accommodative for longer, could well pave the way for another round of global monetary easing over the next few weeks and months as emerging market central banks will be able to roll back some of their defensive tightening measures and some developed market central banks may try to nurture their recoveries," Fels said.
(Read more: Bernanke likelier to boost QE than to taper: SocGen)
Some are expecting the quantitative easing taps to keep running in the U.S. amid the shutdown. "Markets at the moment are taking the view that the U.S. Fed stands behind the government. So if this fiscal problem continues, the market view is that the pumps will keep running, the money will keep flowing into the global system," Michael McCarthy, chief market strategist at CMC Markets, told CNBC.
Others are also expecting more easing measures in Europe.
Despite signs of improvement in the eurozone's economy, Credit Agricole expects the European Central Bank, or ECB, will announce another long-term refinancing operation, or LTRO, which injects "cheap money" into the banking system.
(Read more: Why the shutdown could mean no tapering this year)
While the Eurozone exited its recession in the second quarter, "'green shoots' are becoming less 'green.' Recent leading indicators point to upside risks to near-term growth estimates, but hard data have been more mixed," Credit Agricole said in a note.
"The European recovery will turn into another recession" in the event the U.S. stalemate leads to a debt default, Antonio Fatas, a professor of economics at Insead business school, told CNBC.
But others aren't as certain more measures are on the cards.
Shane Oliver, chief economist at AMP Capital, doesn't expect the shutdown to result in additional global easing measures unless it continues for a long period.
"In the current quarter, the impact wouldn't be big enough to justify" moves by central banks outside the U.S., he said. Economists are forecasting the shutdown may wipe as much as 0.5 percentage point from U.S. economic growth in the fourth quarter.
But he added, "it would be enough for the U.S. Federal Reserve to delay their tapering into next year some time."
— CNBC.Com's Leslie Shaffer; Follow her on Twitter @LeslieShaffer1