Outside a currency exchange in Karachi, Pakistan, where the rupee weakened last week to a record low against the dollar.

Investors enter the week in a mood of increasing nervousness about the global economy, with deteriorating growth in the United States, Europe and Japan now beginning to bite into once high-flying emerging markets.
It is a concern that was underlined last week when the MSCI benchmark for emerging market stocks fell to its lowest level in nearly a year, taking the index down by about 28 percent from its all-time high in November.
The emerging market index, moreover, has been underperforming its developed market counterpart, even though that, too, has been battered by the credit crisis and the ensuing economic slowdown.
While stocks in developed markets as measured by MSCI have lost around 9 percent over the past two months, emerging markets are down 13 percent.
Part of the decline is the result of normal trading patterns in which emerging markets outperform when risk appetite is high and underperform when, as now, it is low.
But it also reflects a growing belief among investors that growth in the world economy is at risk, andwith it the emerging markets that has been a powerhouse of growth in recent years.
‘‘Certainly weaker euro-zone economic growth, weaker U.S., weaker U.K., is bad news for emerging markets,’’ said Gabriel Stein, senior international economist at Lombard Street Research, an investment advisory firm.
‘‘I would be surprised if we don’t see some weakness over the next six months, if not faster than that.’’ A main area of concern will be the so-called BRIC markets—Brazil, Russia, India and China. Although growth remains robust in all four countries, there are signs of trouble.
China, for example, has seen a slowdown in factory output because of weaker export demand while India is expected to fall short of the Indian central bank’s targets for growth.
Hong Kong, something of a proxy for Chinese exports, said Friday that its economy shrank by a seasonally adjusted 1.4 percent in the second quarter, as exports and consumption slowed sharply.
‘‘The global economic and financial turmoil is starting to take its toll,’’ said Rob Subbaraman, senior economist for Asia at Lehman Brothers.
One spillover from this has been the tumble in commodity prices. Oil , for example, has fallen more than 20 percent from its record high above $147 a barrel last month, partly on the assumption that demand will slow.
Similarly, the price of copper, used extensively in the power and construction industries, has fallen about the same amount since the beginning of last month.
Such declines, which will continue to be a focus for investors this week after sharp moves last week, have prompted investors to cool their concerns about global inflation.
About 49 percent of respondents in Merrill Lynch’s August poll of fund managers, for example, said they now expected global inflation to be lower in 12 months’ time. Two months earlier, 59 percent were expecting it to be higher.
If inflationary pressures do ease, that will give central banks room to take actions like cutting interest rates to stimulate growth. Any expectations of that would probably increase demand for government bonds and could give equities a lift.
Lower commodity prices, meanwhile, are a mixed bag for emerging markets, since they reduce revenue in producing countries but help ease domestic food and energy prices.
‘‘There will be winners and losers,’’ said Jacqueline Aldous, head of research at the investment firm Crosby Forsyth. ‘‘You’ve got a range of countries that are commodities and oil plays such as Brazil and Russia, and Asia, which is a purchaser of oil.’’ The increase in investor concerns comes primarily from the spread of economic pain that first showed up in the United States into othe rmajor economies.
Data last week showed that the euro zone joined Japan on the path to a recession—technically defined as two successive quarters of growth contraction —after its gross domestic product contracted in the second quarter.
The broadening of economic woes has made U.S. assets more popular, enhancing the dollar as overseas investors have bought in as a haven and U.S. investors have returned home.
With the dollar index, a gauge of the dollar against a basket of major currencies, rising around 5 percent over the past two weeks alone, investors will be particularly focused on currency fluctuations.
They will also search for signs that the U.S. economy is stabilizing, now that growth in the rest of the world is beginning to slow. Housing has been the cause of much of the U.S. economy’s pain, but two consecutive U.S. housing reports over recent weeks have been better than forecast.