"It's more like a catch-up to some extent," Sheard said, adding that even if the Japanese government had accomplished its goal, the expansion rate of the Japanese central bank balance sheet would stand at only 160 percent.

Toshiro Mutoh, a former deputy governor of the Bank of Japan and currently the chairman of Daiwa Institute of Research, said the Japanese central bank's plan to shore up the economy by aggressively injecting market liquidity through long-term bonds purchases is "a good experiment", as it has no other instruments at hand to get rid of deflation.

He said the bold move has had some positive effects and the market reaction seems "supportive".

Mutoh said the risks of an asset bubble and high inflation would still exist in the next couple of years for Japan, while the timing and the nature of how to exit easing policies remains a problem.

Christine Lagarde, managing director of the IMF, said monetary policies have limits in their effectiveness and may include unintended consequences.

Speaking on Sunday at the Boao forum, she praised the Bank of Japan's move as a "welcome step" for global economic recovery.

Although a substantial portion of the global economy has improved compared to a year ago, particularly in the US, some risks such as a "patchy recovery" concerning Europe persist, Lagarde said.

Georges Ugeux, chairman and CEO of the New York-based Galileo Global Advisors, said it's important for China to remain prudent and maintain moderate renminbi appreciation given the recent developments in major economies.

"Chinese authorities have realized the crisis in Europe is not over yet, and one shouldn't rush to change things until the situation becomes more stable."

He said China is currently pursuing the right monetary policies.

"As for the growth of the world economy, we don't need more than the Chinese government is doing at the moment, because everybody ignores that we have already technically seen a 25 percent increase in the value of the renminbi over the past three to four years."