LONDON (Reuters) – One of the biggest worries about this month’s sudden seizure in world markets is how puzzled investors have been left by it, and how many are just wishing it away as a temporary blip.

History suggests governments and central banks would do well to sit up and take notice, but with policy coordination at its lowest ebb in decades, a coherent response is unlikely.

With almost $6 trillion wiped off the value of global stock markets since the start of the year and another 25 percent off already low oil prices, there is a real risk investor anxiety itself will be the catalyst for a world recession.

And when market turbulence starts to crystallize the very problem investors are worried about — what wonks call a negative feedback loop — then these rare but dangerous spirals in confidence are notoriously difficult to halt.

By any measure, we are in historic territory.

Over the past 28 years — or 336 months — only 12 months have seen bigger losses in the MSCI World stock index than January 2016. Over half of those were associated with major market crises, including the Lehman Brothers bust of 2008-09, the dot.com implosion of 2001-02 and the emerging markets crash of the late 1990s.

Lowering the International Monetary Fund’s 2016 world growth forecast by another 0.2 percentage points to 3.4 percent this week, IMF chief economist Maurice Obstfeld said markets were reacting ‘very strongly’ to bits of evidence in a volatile, risk averse climate — but one where little fundamental had changed.

His predecessor Olivier Blanchard, now writing for Washington’s Peterson Institute, sympathizes with that view but warned against ignoring the seizure in markets.

“How much should we worry? This is where economics stops giving an answer,” Blanchard said.

“If … the stock market slump lasts longer or gets worse, it can become self-fulfilling. Low stock prices lasting for long lead to lower consumption, lower demand, and, potentially, to a recession.”

U.S. bank Morgan Stanley said on Tuesday it now sees a 20 percent chance of a 2016 world recession, as defined by sub-2.5 percent growth rate that is needed to keep pace with population gains.

FEAR ITSELF?

But why all the new year panic? Most economists blame a confluence of events rather than any sudden shock.

China’s deepening slowdown, pressure to devalue its yuan and its increasingly perplexing currency policy are all potential game-changers but have been building for months.

So too has the collapse in oil prices and other commodities, now more than 18 months old albeit a seemingly bottomless slide that is feeding off the China concerns.

These were joined last month by the first rise in U.S. interest rates in a decade which, by bolstering the already pumped-up U.S. dollar, has arguably exaggerated both the oil price fall and China’s yuan conundrum and capital flight.

Add to that potent mix the currency, commodity and interest rate pressures on emerging countries from Russia and Brazil to South Africa and the Gulf, an unwinding of these countries’ sovereign investments overseas, and investor flight from the equity and bonds of energy and mining companies.

Everyone can see a spiral forming, but few see where it ends. The threat of a major re-set of global market valuations amid high volatility is enough for many conservative investors to go to ground until it all plays out.

The now famous “sell (mostly) everything” note issued by Britain’s RBS last week was not a mere throwaway. It focused on the risk of markets snowballing as world trade and credit growth struggle, currency wars go up a gear and China and oil feed off each other. A 10-20 percent stock reversal was its best guess.

“The world is in trouble,” it said.

If so, where’s the cavalry?

By consensus, there appears to be about as much chance of a confidence-boosting grand economic policy agreement this year as there is of oil prices returning to $100 a barrel.

Coincidentally, China chairs the G20 group of world economic powers this year. Finance chiefs meet in Shanghai next month.

But internal dilemmas mean global coordination is likely to be low on Beijing’s priority list.

The U.S. Federal Reserve also paid little heed to international concerns when hiking rates last month, while Saudi Arabia has shown scant consideration for other oil exporters as it plays out a crude price war to protect market share against U.S. shale producers.

Germany has been at loggerheads with much of the rest of the euro zone and G7 partners for years over fiscal policy and austerity.

Harvard economist Jeffrey Frenkel notes that global economic cooperation has been stymied by international differences and domestic political divisions on policy, as well as growing disagreement between economists on how to model the world.

“When two players sit down at the board, they are unlikely to have a satisfactory game if one of them thinks they are playing checkers and the other thinks they are playing chess,” he wrote in a paper this month.

(Additional reporting by Jamie McGeever; Editing by Catherine Evans)