Preface
Auctions have been used since antiquity. For instance,
the Roman Empire was once sold at auction. Today, auctions
are seemingly pervasive: the institution is used to
sell a variety of agricultural commodities and natural resources—
from aubergine to tobacco, from fish to oil to
timber—as well as fine art, real estate, and used cars. In
addition sealed-bid tenders (an auction format) are used
extensively by both firms and governments to procure a
variety of goods and services such as weapons systems and
tree-planting services. The Internet auction house eBay is
an integral part of the American and world economies. By
any measure, the volume of trade on eBay and similar sites
is unparalleled in world history.
People around the world google thousands of times
each second, the results of their requests appearing in the
iconic results page—the organic results on the left and
the advertised ones to the right, separated by merely a
few whitespace characters. The order of those links on the
right is determined at a position auction, a type of auction
that has generated billions in revenues for Google. In
short, it is impossible to live in the world today without
being affected by auctions.
Despite the importance of auctions, except for a modest
number of economists with special training, few understand
beyond a simple level how these mechanisms really work.
In fact most people are unaware that different auction
formats and pricing rules even exist. To be sure, many
books (search “eBay auctions” under Books on Amazon.
com) provide concrete advice concerning how to buy or
to sell on eBay. Others provide practical advice concerning
how to sell real estate or to buy used cars at auctions.
However useful these books may be, they do not explain
when and why auctions work so well, or how. Several advanced
textbooks, aimed mostly at graduate students and
professional economists, have been written since 2000
documenting the progress economists have made in understanding
purposeful, equilibrium behavior at auctions;
for example, see the books by Vijay Krishna (2002, 2010),
Paul Klemperer (2004), and Paul R. Milgrom (2004). But
these books are really at levels beyond what most people
can be reasonably expected to explore. The book by Kenneth
Steiglitz (2007) is easy to read, but devoted mostly to
eBay auctions. By writing this book, we hope to fill a niche,
providing material that is straightforward to understand,
yet rich enough to inform—in short, the essentials.
In chapter 1 we motivate the study of auctions by
outlining what we consider an auction to be, describing
commonly employed auctions and characterizing environments
within which auctions are most helpful. Equipped
with this overview, in chapter 2 we then turn our attention
to modeling auctions. Economists consider auctions to be
examples of games of asymmetric information—some
players know something that other players do not. For
example, at some auctions, each bidder might know what
an item is worth to him but not how rivals value the item.
The seller presumably knows even less: not only might the
seller not know a particular bidder’s valuation, he likely
won’t even know which bidder values the item the most.
Adopting a baseline model, in chapter 3 we characterize
equilibrium behavior under the common auction formats
and pricing rules, discussing important properties of the
outcomes at auctions. In chapter 4 we examine the implications
of using other auction rules and different modeling
assumptions, contrasting the outcomes with those of the
benchmark model. We devote chapters 5 and 6 to deeper
examinations of specific environments—procurement
and Internet auctions, respectively. Such settings allow us
to investigate the incentives at play at auctions that are
important in modern economies. While the focus in the
first six chapters is primarily on settings in which a single
object is at auction, in chapter 7 we discuss auctions at
which multiple units of the same good or several different
objects are for sale, using online ad auctions in chapter 8
as an outlet for an in-depth discussion of some of the issues
that arise in those settings. We reflect on what has
been covered by collecting some final thoughts in chapter
9. At the end of the book we provide a glossary that collects
important terms and definitions that may be helpful
in reading the book and, in a separate section, list other
resources that interested readers can use to learn more
about auctions.