Pat Gunning wrote: "The textbook and professional terminology nowadays defines shock as a shift of aggregate demand or supply that is not caused by government." The qualification "not caused by the government" is not right. "Monetary policy shock" and "fiscal policy shock" are perfectly idiomatic in modern macroeconomics. For example, if a central bank can be characterized as following a reaction function, a random departure from that function is known in the vector autoregression (VAR) literature and the optimal monetary policy literature as a monetary policy shock. Kevin Hoover