The global economy is bound to remain leaderless, as G-20 countries meeting in Shanghai on Friday are unlikely to produce anything more than a rhetorical statement, Citigroup's chief economist Willem Buiter said.
Buiter said Friday the global economy truly needs an agreement on exchange rates that will be defended through intervention, as well as expansion of supportive monetary policy, fiscal stimulus modulated according to countries' needs, and "supply side reforms that sustain animal spirits in the corporate sector."
"You're not going to get any of that in substance. There is no leadership in the global economy. And there is no willingness to forgo the short-run benefits of beggar-thy-neighbor exchange rate depreciation. Currency wars will be the reality of what we'll see over the next few years," he told CNBC's "Squawk on the Street".
Buiter and Citigroup analysts said in a note Wednesday the risk of the global economy falling into a recession is rising as fundamentals remain poor.
"We are currently in a highly precarious environment for global growth and asset markets after two to three years of relative calm," Citigroup said, noting that global growth was "unusually weak" in the fourth quarter at around 2 percent.
Buiter said central banks are nearly out of ammo when it comes to using conventional and unconventional monetary policy as a means of stimulating demand.
"If we have a further slowdown, it will have to be combined more with the fiscal policy, and the world just isn't ready for that, institutionally, politically and any other way," he said.
At the same time, the private and public sectors in most advanced economies have become highly leveraged, he noted.
Citi is not expecting a U.S. recession, provided no surprises from abroad send the dollar sharply higher. But it does anticipate a further incremental slowing in the absence of a supportive Federal Reserve and as corporations ratchet up debt following a period of "unspectacular, mediocre" growth, he said.
Markets have appropriately priced in the risk of recession following last year's "excessive optimism," he said.
"Markets are ahead of the policymakers here for once," he said. "People have now rediscovered that, yes, future earnings growth projections on which the stock valuations were based were unrealistic."