They can be adverse – consider the sudden reduction in risk appetite and drying up of liquidity in international financial markets in 2008. Shocks can also be positive – consider the way the entry of China into the global economy and the development of the efficient east-Asian manufacturing production chain in the 1990s lowered costs of consumer goods for the world.
Or of the way Australia's terms of trade have, for the past decade, been way above their historical average. BIS central bankers’ speeches  1  The effect of the terms of trade fall on which our public discussion typically focuses is the impact on the Federal government's fiscal position.