The global economy is stuck in a rut that it won't exit unless governments revolutionise policies and how they invest, rather than just hoping for a cyclical upswing, the OECD said.

The latest outlook and policy prescriptions from the Paris-based group mark a step beyond its repeated warnings about threats to growth from US-China tensions, weak investment and trade flows. Those remain, but it also flags more systemic challenges from climate change, technology and the fact that the trade war is just part of a bigger shift in the global order.

For OECD Chief Economist Laurence Boone, the worry is that the world could continue to suffer in the decades to come if authorities offer short-term fiscal and monetary fixes as the only response.

"The biggest concern… is that the deterioration of the outlook continues unabated, reflecting unaddressed structural changes more than any cyclical shock," Boone said. "It would be a policy mistake to consider these shifts as temporary factors that can be addressed with monetary and fiscal policy: they are structural."