The Law of Demand (NEW 2016)

Our study of market economies requires us to examine both the demand-side and the supply-side of product and resources markets. Buyers and sellers interact with one another to engage in mutually beneficial exchanges in a market economy, and prices are set based on the demand and supply for a particular good, service or resource. This video lesson presents the law of demand, and explains how the demand curve can illustrate this fundamental economic concept.

The Business Cycle – Illustrating the Economy’s Booms and Busts

The business cycle model is one often referred to in the media, which likes to use terms like “boom’ and ‘bust’. It is a model that can communicate several important pieces of information about a nation’s economy. Basically, the business cycles is a graph which shows the level of real GDP over time. The vertical axis shows the level of GDP, and horizontal axis time.

A typical nation’s business cycle will most likely look like a wave, showing how GDP rises and falls over time. Assuming the country is achieving economic growth over the long-run, business cycle’s ‘line of best fit’ or ‘trend line’ will slop upwards, indicating that over the span of years or decades, a nation’s economy will produce more output. But over shorter periods of time, output may fluctuate, as the economy experiences those ‘booms and busts’ the media are so fond of.

There are four fundamental phases in any nation’s business cycle:

  • Expansion: Also known as the recovery phase, when the nation’s output is rising at a rate faster than the long-run trend.
  • Peak: This is the end of a period of expansion, when output begins to decline
  • Contraction: Also known as the recession phase, when the nation’s output is falling over time.
  • Trough: This is the end of a period of recession, when output begins to recover (the economy enters an expansion phase again).

This video lesson will explore the four phases of a nation’s business cycles and explain how the goal of macroeconomic policies is to ‘smooth out’ the fluctuations in the business cycle, and thereby reduce the amount of uncertainty faced by a nation’s households and firms regarding the future level of economic activity.

The Law of Increasing Opportunity Cost and the PPC Model

In a previous lesson we introduced the basic economic concepts of scarcity, opportunity cost, and the production possibilities curve (PPC). In that lesson, we examined the tradeoffs an individual faces in the use of her time between “work” and “play”. We showed that the opportunity cost of one hour of work is always the one hour of play that the individual could have enjoyed instead.

The constant opportunitiy cost between work and play is illustrated in the PPC model as a straight line production possibilities curve. In this lesson, we will expand our understanding of the PPC and opportunity costs by examining the tradeoff a nation faces between the production of two goods using its scarce resources. Cars and pizzas require very different resources to produce, and therefore, as the production of one good increases, the opportunity cost of its production in terms of the other good increases.

The result is a PPC that is bowed outwards from the origin. When choosing between the production of two goods, the more similar the resources needed to produce each good, the straighter the PPC will be. The less similar the resources needed to produce each good, the further the PPC will be bowed out from the origin.

The Circular Flow Model of a Market Economy

By this point in your course you may have learned the definition of a market: A place where buyers and sellers meet to engage in mutually beneficial exchanges. But what is a market economy? Two basic types of markets exist in any market economy: resource markets and product markets. The exchanges that take place in these markets benefit both the households and the firms that engage in exchanges.

This lesson will introduce the circular flow of money, resources and goods and services in a market economy. We will examine how resources flow from households to firms, and goods and services from firms to households. We will also seek to explain why individuals are willing to engage in the exchanges that characterize the market system.

To order practice activities on this and other lessons from the Econ Classroom, click here.

For student revision guides and teacher PowerPoints, click here.

Scarcity, Opportunity Cost and the Production Possibilities Curve

The basic economic problem is one rooted in both the natural world and in human greed. We live in a world of limited resources, but we seem to have unlimited wants. This results in scarcity, which gives rise to the very field of Economics, which deals with how to allocate scarce resources between the competing wants and needs of society.

This lesson will introduce these basic economic concepts, along with the first (and perhaps the most useful) graph an Economics student will learn, the Production Possibilities Curve.