A variable that tends to move in advance of aggregate economic activity is called

Central banks:

A. exist in almost every major nation. B. are common only to industrialized nations. C. in the United States oversee the U.S. economy, as well as some developing nations who do not have a central bank. D. stopped being used after events like the Great Depression proved them useless.

Assume that the marginal propensity to consume in an economy is 0.9. If the economy's full-employment real GDP is $500 billion and its equilibrium real GDP is $550 billion, there is an inflationary expenditure gap of

A. $5 billion. B. $500 billion. C. $100 billion. D. $50 billion.