First, a significant rise in inflation could choke the expansion by forcing central banks to tighten policy more than expected. This typical postwar scenario moved into focus last year, even in the absence of any evidence of a resurgence of inflation.
Second, and less appreciated, serious financial stress could materialise as financial cycles mature if their contraction phase were to turn into a more serious bust. This is what happened most spectacularly with the Great Financial Crisis (GFC).
Third, short of serious financial stress, consumption might weaken under the weight of debt, and investment might fail to take over as the main growth engine. There is evidence that consumption-led growth is less durable, not least because it fails to generate sufficient increases in productive capital.
Fourth, a rise in protectionism could challenge the open global economic order. History shows that trade tensions can sap the global economy’s strength
This zerohedge.com report was valuable, I suggest you read it.
*One more point from the report that I wish to highlight is the known effects from what the central banks propping up the markets means.
One piece of advice: record high stock prices and record low volatility as a result of what Citi called "forced buying", which is also known as "buying without conviction"...
Every time central banks scale back, investors head for the exit.