Deflation feeds global fears.

Was the taper a mistake?

Risk of Deflation Feeds Global Fears
By JON HILSENRATH and BRIAN BLACKSTON

Updated Oct. 16, 2014 12:01 p.m. ET

Behind the spate of market turmoil lurks a worry that top policy makers thought they had beaten back a few years ago: the specter of deflation.

A general fall in consumer prices emerged as a big concern after the 2008 financial crisis because it summoned memories of deep and lingering downturns like the Great Depression and two decades of lost growth in Japan. The world’s central banks in recent years have used a variety of easy-money policies to fight its debilitating effects.

Now, fresh signs of slow global economic growth, falling commodities prices, sagging stock markets and declining bond yields suggest the deflation risk hasn’t gone away, particularly in the often-frenetic eyes of investors. These emerging threats come as the Federal Reserve is on track this month to end a bond-buying program that has been one of the main tools in its fight against falling prices.

The deflation concern is particularly pronounced in Europe and Japan, two economies where policy makers are struggling to come up with solutions to counter especially slow economic growth.

However, recent declines in commodities prices suggest that downward pressure on inflation—if not all-out deflation—could become a wider-ranging phenomenon, and one with some mixed implications for economies like the U.S. and emerging markets.

Investor worries about the global economy appeared to gather force Wednesday. European stock markets sagged; the Stoxx Europe 600 index fell 3.2% to its lowest level since last December. U.S. stocks pared steep losses, but still finished down for the fifth straight day; after falling more than 450 points at one point, the Dow Jones Industrial Average fell 173.45, or 1.1%, to 16141.74.

Meantime, yields on 10-year U.S. Treasury notes fell to 2.091%, their lowest level since June 2013, and are down nearly a percentage point from the beginning of the year. Bond yields fell to new lows in Germany, too. Crude-oil prices dropped further; crude futures on the New York Mercantile Exchange fell to $81.78 a barrel, the lowest level since June 2012.

The deflation concerns are particularly acute in Europe, where annual inflation in the 18 nations that use the euro was 0.3% last month, a five-year low that is far below the European Central Bank’s target of just under 2%.

With inflation so low, it wouldn’t take much of a shock—such as weakness in Germany’s economy or geopolitical tensions in nearby Ukraine—to tip the whole region into a deflationary downturn. Some eurozone countries, such as Italy, have already tipped into deflation. Even countries outside the currency bloc are feeling the pain. Sweden’s statistics agency said Tuesday that consumer prices fell 0.4% in annual terms last month after a 0.2% fall in August, well below its central bank’s 2% target.

The risk of deflation in Europe is “a real worry,” Harvard University professor and former Federal Reserve governor Jeremy Stein said in an interview. “The right prescription [for policy makers] is to be aggressive.”

ECB President Mario Draghi acted against deflation risks in June and September, pushing the central bank to slash interest rates to record lows each time—including a negative rate on bank deposits at the ECB—and unveiling new bank-lending and asset-purchase plans for asset-backed securities and covered bonds.

But there is little consensus for more-dramatic measures—the kind of monetary stimulus the Fed, the Bank of England and the Bank of Japan have deployed—namely large-scale purchases of government bonds to raise the money supply.

The head of Germany’s central bank, Jens Weidmann, has signaled his opposition to such bond buying, and other members of the ECB’s governing council appear sympathetic to his argument that with government and corporate borrowing costs already superlow, the policy wouldn’t even do much good.

“I am very much for a steady-hand approach, and I think this is what we are doing,” Austria’s central bank governor, Ewald Nowotny, said in an interview last week.

Hard fiscal problems are part of Europe’s problem. Last week, Standard & Poor’s stripped Finland of its triple-A credit rating and downgraded France’s outlook. On Tuesday, Fitch put France on review for a possible downgrade.

Struggling economies such as France and Italy face a tough choice: Take additional austerity measures to shrink budget deficits, inflicting more pain on their economies, or attempt to flaunt the EU’s budget rules calling for low deficits, which could damage their credibility in Europe.

The resistance Mr. Draghi faces has shaken the faith of some investors that policy makers in Europe will address the threat.

“Market valuations, especially for rich countries, have been well above what was warranted by fundamentals. What kept them up there was a belief that central banks were markets’ best friends,” said Mohamed El-Erian, chief economic adviser at Allianz Group. “Most people now recognize that the ability of central banks to address what ails the global economy is weaker than they believed.”

Meanwhile, Japan had recently begun to stir sustained growth, which helped to push its inflation rate above 1%, after years of on-again, off-again deflation. But inflation decelerated again in recent months as the economy softened after an April sales-tax increase meant to restrain mounting government debt. Many private economists forecast a slip back below 1% this year.

Japanese officials must now decide whether to follow through on another planned sales-tax increase that could dent growth even more. And the Bank of Japan is weighing whether it needs to provide even more stimulus. BOJ Governor Haruhiko Kuroda launched new asset purchase programs last year to reverse two decades of deflation and has pledged to persist until he reaches the 2% target.

Japan’s struggles to exit deflation, even with massive central-bank stimulus, illustrate just how difficult it is for an economy to pull out of the trap, once it has settled in.

A weak global outlook “has to be a worry for every economy,” Reserve Bank of India Governor Raghuram Rajan told The Wall Street Journal in an interview last week.

The U.S. confronts much different circumstances than Europe and Japan. U.S. inflation had been rising toward the Fed’s 2% objective earlier this year but now faces a downward tug amid the weakening global growth and a strengthening U.S. dollar. The Labor Department reported Wednesday that producer prices in the U.S. fell in September. Sharp drops in commodities prices this month could add to downward pressure.

Yet falling commodities prices have silver linings. For one, the decline is being driven in part by a U.S. energy production boom—not just sagging global demand for goods. Moreover, falling gasoline prices are a boon to U.S. consumers: One rule of thumb is that every one-cent drop in the price of gasoline amounts to a $1 billion boost to U.S. household incomes, and gasoline prices have dropped by 13 to 17 cents from a year ago, according to the automobile group AAA.

“All else equal, when energy gets cheaper, we benefit,” Mr. Stein said.

Meanwhile, the Fed is on track this month to end its bond-buying stimulus program launched in September 2012. And Fed officials have largely stuck to their line that they expected to start raising short-term interest rates by the middle of 2015. Still, traders in futures markets have been pushing up the prices of contracts tied to the Fed’s benchmark interest rate—a sign they see diminishing odds that the Fed will follow through on that plan.

Harvard’s Mr. Stein said he didn’t think the U.S. central bank needed to alter its thinking much in light of recent developments. “I wouldn’t dramatically revise my expectations,” he said. “The balance of the job-market news in the U.S. has been very positive.”

A Commerce Department report Wednesday showed U.S. retail sales dropped in September, but many economists are sticking to estimates that the U.S. economy expanded at a rate in excess of 3% in the third quarter, potentially the fourth time in the past five quarters it exceeded 3%. Moreover job growth has been stronger than Fed officials expected.