Workers in the developing world facing higher prices have been increasingly vocal in demanding higher wages, with protests erupting in recent days in Vietnam, Cambodia and Egypt.

At the same time, inflation keeps rising: the Philippines announced that its inflation at the consumer level had doubled in the last five months, showing a 6.4 percent increase in March over the same month a year ago. And weekly inflation at the wholesale level has accelerated in India, reaching an annual rate of 7 percent in the week ended March 22, up from 3.1 percent as recently as last October.

Not long ago, it would have been unlikely for a poor country with high inflation to see its money strengthen in value against the mighty dollar. But the dollar is not quite as mighty as it once was. Large American trade deficits and other problems have weakened its appeal.

And there are signs that the dollar could fall further if developing countries’ central banks stopped supporting it, particularly in Asia.

Vietnam’s central bank even had to order the country’s commercial banks late last month to resume buying dollars within the tight range of exchange rates set by the government. Many banks had started betting on dollar depreciation and refusing to accept large sums in dollars, to the point that multinationals and exporters had trouble wiring money into the country to pay their employees’ salaries.

Additionally, the dollar’s weakness is itself a cause of inflation in developing countries, particularly those that have barely let their currencies rise against the dollar in an effort to hold on to export markets.

In a street market around the corner from the 270-year-old Lungshan Temple in Taipei, Taiwan, Teresa Gau, a fishmonger, is charging up to a third more for fish and crabs than she did a year ago. That is because fishing boat owners are charging her more as they struggle to cover higher costs for diesel fuel, which is priced in dollars.