economics.quest

equilibrium P Q
THEOREM

The Law of Supply

As the price of a good increases, the quantity supplied increases, ceteris paribus. Producers are willing to supply more at higher prices because higher prices increase the potential for profit.

PARADOX

The Paradox of Thrift

When everyone saves more, total savings may decrease. Individual prudence becomes collective harm: reduced spending leads to reduced income, which leads to reduced ability to save.

QUOTE

"It is not from the benevolence of the butcher, the brewer, or the baker that we expect our dinner, but from their regard to their own interest."

-- Adam Smith, 1776
THEOREM

Comparative Advantage

A country benefits from trade even if it can produce every good more efficiently than its trading partner. What matters is relative efficiency -- opportunity cost -- not absolute productivity. Ricardo's proof remains one of the most counterintuitive and powerful results in economics.

PARADOX

The Diamond-Water Paradox

Water is essential to life yet nearly free. Diamonds are frivolous yet enormously expensive. The resolution: price reflects marginal utility, not total utility.

QUOTE

"The long run is a misleading guide to current affairs. In the long run we are all dead."

-- John Maynard Keynes, 1923
THEOREM

Elasticity

The responsiveness of quantity demanded to a change in price. Necessities are inelastic (demand barely changes); luxuries are elastic (demand swings widely). Tax incidence falls on the less elastic side of the market.

QUOTE

"The curious task of economics is to demonstrate to men how little they really know about what they imagine they can design."

-- F.A. Hayek, 1988
PARADOX

Jevons' Paradox

Technological improvements that increase the efficiency of resource use tend to increase total consumption of that resource, not decrease it. More efficient engines lead to more driving, not less fuel consumed. Efficiency is not conservation.

THEOREM

Diminishing Returns

Adding more of one input while holding others constant will eventually yield smaller and smaller increases in output. The tenth worker in a factory adds less than the second.

SIX QUESTIONS

What is scarcity?

The fundamental condition that human wants exceed available resources, forcing every society to make choices about allocation.

What is opportunity cost?

The value of the next best alternative forgone when a choice is made. Every decision has a shadow price.

What is equilibrium?

A state where no participant has an incentive to change behavior. The price at which quantity demanded equals quantity supplied.

What is an externality?

A cost or benefit that affects a party not directly involved in a transaction. Pollution is the textbook negative externality.

What is comparative advantage?

The ability to produce a good at a lower opportunity cost than another producer. The basis for mutually beneficial trade.

What is moral hazard?

The tendency to take greater risks when insulated from consequences. Insurance, bailouts, and guarantees all create moral hazard.

THE LIBRARY

The Wealth of Nations
Capital
The General Theory
Free to Choose
The Road to Serfdom
Development as Freedom
Thinking, Fast and Slow
Capital in the 21st Century
The Affluent Society
Principles of Economics
Debt: The First 5,000 Years
Nudge
The Worldly Philosophers
Capitalism and Freedom
Why Nations Fail
There is no free lunch. Incentives matter. Trade creates value. Markets fail. Governments fail too. Sunk costs are sunk. Correlation is not causation. People respond to incentives. Everything has a cost. There is no free lunch. Incentives matter. Trade creates value. Markets fail. Governments fail too. Sunk costs are sunk. Correlation is not causation. People respond to incentives. Everything has a cost.

economics.quest -- a journey through the dismal science