Emerging markets rout stirs unease about capital curbs

Christian Keller, head of economics research at Barclays, said struggling governments will prefer to go to the IMF or wealthier countries for assistance, while soft curbs such as taxes are ineffective during a market meltdown.

"If everything is going belly-up, you won't care about paying a tax to exit and save some of your investment," he added.

The clincher may be the extent of the selloff, because spiralling inflation and currency collapse are difficult for voters to stomach.

Malaysian stocks and the ringgit are down about 20 percent this year compared with an 80 percent plunge during the 1998 crisis, noted Bank of America Merrill Lynch analysts.

But central bank intervention has depleted reserves by $25 billion this year, while Malaysia is also deep in political crisis, meaning capital controls can't be ruled out, they said. - Reuters