Module 4 krugman 2
• Ask students to raise their hand if, after studying consumer and producer surplus, they
think markets are efficient. Hopefully most or all will have gotten that point. Then ask
them to raise their hand if they think markets are fair. Ask those who don’t raise their hand
why they didn’t. Of course, many may not be willing to raise their hand for anything, but
you should be able find someone who is actually skeptical of markets. Finally, ask students
if they think that markets are always efficient and the best way to allocate resources.
Hopefully the students will mention monopolies, externalities, and individual versus
aggregate welfare (though likely not using those specific terms). Use the discussion to lead
into your presentation of market failures.
• Ask students who owns the air we breathe and the fish in the sea. Have them come up with
other examples of markets where property rights aren’t well defined.
Presenting the Material
• Emphasize that there are two main points in this Module: (1) Markets, when they have
certain characteristics, are efficient. (2) Markets sometimes fail (i.e., sometimes they do
not have those certain characteristics).
• Discuss the importance of property rights by getting students to think about what happens
when property rights do not exist, or are not well defined. What happens, for example, if
after you buy a good you do not have the right to resell it? Many mutually beneficial
Module Outline
I. Consumer surplus, producer surplus, and the gains from trade
A. The gains from trade
1. Both consumers and producers gain in a specific market—there are gains from trade.
This is why everyone is better off participating in a market economy than they would
be if each individual tried to be self-sufficient. This is illustrated in text Figure 9-1,
shown here.