Economics

The elasticity of demand is its responsiveness to changes in another factor, such as price. British economist Alfred Marshall is generally credited as the first economist to define the concept in 1890, but the German statistician Ernst Engel published a paper five years earlier, showing how changes in income alter the level of demand. The origins of the concept may be disputed, but its importance is not.

IN CONTEXT:

FOCUS

Welfare economics

KEY THINKER

Vilfredo Pareto (1848–1923)

BEFORE

1776 Adam Smith’s The Wealth of Nations relates self-interest to social welfare.

1871 British economist William Jevons says that value depends entirely on utility.

1874 French economist Léon Walras uses equations to determine the overall equilibrium of an economy.

AFTER

1930–50 John Hicks, Paul Samuelson, and others use Pareto optimality as the basis of modern welfare economics.

1954 US economist Kenneth Arrow and French economist Gérard Debreu use mathematics to show a connection between free markets and Pareto optimality.

Perhaps the most widely quoted and influential definition is that of Burns and Mitchell (1946, p.l) who state that:

Business cycles are a type of fluctuation found in the aggregate economic activity of nations that organize their work mainly in business enterprises:

Managing Complexity

The U.S. economy consists of millions of buyers and sellers of goods and services. Think about all the economic activity near where you live. Even in a small town there are dozens of businesses, hundreds of workers, and thousands of items that could be purchased on any given day. You could not possibly keep track of all the decisions that affect the economy of a small town.

The possibility that the financial system might be a source of instability leading to crises was frequently discussed in pre-Keynesian business cycle literature, which is reviewed briefly in the next section. The main focus of the chapter is the revival of interest in the financial instability hypothesis (FIH) in the 1970s and 1980s.