Econ 522
Economics of Law
Dan Quint
Spring 2010
Lecture 2
Logistics
 If you’re still trying to get into the class, see me after lecture
 Sample exam questions posted online
 TA sections begin this Friday
 “Fake homework”
1
Last week, we…
 defined law and economics
 saw some brief history of the common law
 and the civil law
 and discussed ownership of dead whales
2
Today: efficiency
 what is efficiency?
 is efficiency a good goal for the law?
3
What is
“efficiency”?
4
First concept: Pareto improvement
 a Pareto improvement is any change to
the economy which leaves…


everyone at least as well off, and
someone strictly better off
 example of a Pareto improvement


Vilfredo Pareto
(1848-1923)
your car is worth $3,000 to you, $4,000 to me
I buy it for $3,500
 an outcome is Pareto superior to another,
or Pareto dominates it, if the second is a
Pareto improvement over the first
5
Pareto superiority is not that useful a
measure for evaluating a legal system
 Pareto improvements are “win-win”



but most new laws create some winners and some losers
so the Pareto criterion usually can’t tell us whether one policy is
“better” than another
even the car example might not be a true Pareto-improvement
 so we need another way to compare outcomes
6
Next concept: Kaldor-Hicks improvement
 a Kaldor-Hicks improvement is any change to the
economy which could be turned into a Pareto
improvement with monetary transfers

also called potential Pareto improvement
 car example again


your car is worth $3,000 to you and $4,000 to me
government takes your car and gives it to me



I’m better off, you’re worse off
but if we combined this with me giving you $3,500, it becomes a Pareto
improvement
so me getting your car is a Kaldor-Hicks improvement
 a Kaldor-Hicks improvement may create winners and
losers, but gains outweigh the losses
7
Example
 You and I are neighbors, you want to throw a party



The party would make me $100 worse off…
…and make you $50 better off…
…and make each of your 30 guests be $5 better off
 Is the party a Pareto improvement?

No – it makes you and your guests better off, makes me worse off
 Is the party a Kaldor-Hicks improvement?


Yes – because the party, combined with the appropriate money
transfers, would be a Pareto improvement
(Example: you throw the party, you give me $40, each of your guests
gives me $3 – that’s a Pareto improvement)
8
To check if something is a Kaldor-Hicks
improvement, we can…
 look for transfers that turn it into a Pareto-improvement…
 …or, just count up the gains of the winners and the
losses of the losers, and see which is bigger
 Kaldor-Hicks improvements may make some people
worse off, but the gains outweigh the losses






if you have the party…
I’m $100 worse off
You’re $40 better off
30 guests are each $3 better off
– $100 + $40 + 30 X $3 = $30 > 0
Gains outweigh losses, so party is a Kaldor-Hicks improvement
9
So…
 A Kaldor-Hicks improvement is any change that
“creates value…”
 But, value is equated with willingness to pay


That is, we said the party made me $100 worse off
We equated my disutility from you making noise with the amount
of money that would replace the inconvenience



If you threw the party and gave me $100, I’d be just as well off as
before
By equating utility with money, we create a way to compare utility
across individuals
But assuming that how badly you want something is equal to
how much you’d pay for it has problems of its own…
10
Efficiency
 a situation is Kaldor-Hicks efficient, or just efficient, if
there are no available Kaldor-Hicks improvements
 In other words, efficiency is when there’s no way to make
some people in the economy better off, without making
some others worse off by more

we’re already getting maximal value out of all available resources
 We’ll also say A is “more efficient” than B if moving from
B to A is a Kaldor-Hicks improvement
11
Example: is it efficient for me to drive to work
instead of taking the bus?
 Bus to school from where I live is free
 Driving is more convenient, but costs me $1 (gas)
 Driving also imposes costs on other people: there’s more
traffic, less parking, more pollution

Suppose when I drive to work, it makes 1,000 other people
worse off by $0.01 each
 If the benefit to me of driving to work is at least $11, it’s
efficient for me to drive; if it’s less than $11, it’s not
12
Some other, similar measures
 our definition of efficiency: all possible Kaldor-Hicks
improvements have already been made
 Ellickson: “minimizing the objective sum of
(1) transaction costs, and
(2) deadweight losses arising from failures to exploit
potential gains from trade”
 Posner: “wealth maximization”
 Polinsky: “Efficiency corresponds to ‘the size of the pie’”
13
What forces lead to
inefficiency
14
To see whether something’s efficient…
 Compare gains to everyone in society (total social
benefit)…
 …to costs to everyone (total social costs)
 Example we just saw (me driving to work):



Total social benefit = whatever the benefit is to me
Total social cost = $1 (gas) + 1,000 X $0.01 = $11
So we just said: it’s efficient for me to drive to campus whenever
the value I get from driving is more than $11
15
But what do people actually do?
 When people decide how to act…
 …they consider the cost and benefit to themselves, not
to everyone

private benefit and private cost
 Driving only costs me $1 in gas – so I’ll drive whenever
value to me is more than $1
 On days where my benefit from driving is more than $1
but less than $11, I drive to work even though that’s
inefficient
16
So externalities cause inefficiency
 Efficiency depends on whether social benefit > social cost
 I’ll do it whenever private benefit > private cost
 If I’m the only one affected by my choices, then social
benefit = private benefit and social cost = private cost

so my choices will be efficient
 But when my choices affect other peoples’ payoffs…


social benefit  private benefit, or social cost  private cost
so actions I choose to take may not be efficient
17
A classic example of this: the Tragedy of the
Commons
 Hardin (1968), “The Tragedy of the Commons”
 Picture a small fishing village on a lake




The more fish I catch, the fewer
fish are left in the lake…
…and the harder it is for everyone
else in the village to catch fish
So my fishing imposes an
externality on everyone else
This means everyone ends up
fishing more than the efficient
amount
18
Tragedy of the Commons – example
 Suppose the town has 20 fishermen
 The cost (disutility, effort) of fishing is 4 fish per hour
 Notation



h = how many hours a day I fish
H = combined hours a day everyone in town fishes (including me)
H = combined hours a day everyone but me fishes
 Fishermen catch 130 – H fish per hour
(a)
(b)
Left to their own devices, how much will each
person fish? How much utility will each person get?
Is this efficient?
19
So, externalities cause inefficiency
 Fishing imposes a negative externality on other fishermen


Each one ignores this externality when deciding how much to fish…
…so they all end up fishing more than the efficient amount
 Same thing happens with other communal resources


Cattle grazing, whaling, overhunting, oyster beds
Elinor Ostrom, who shared this year’s Nobel Prize in Economics,
studies how different societies solve this problem
 Positive externalities work the opposite way

Activities which create positive externalities are done less than the
efficient amount
20
Other forces which
lead to inefficiency
21
So we know externalities can lead to
inefficiency
 Without some sort of intervention…


Activities which impose a negative externality will be done an
inefficiently high amount…
…and activities which impose a positive externality will be done
an inefficiently low amount
 One theme we’ll see in this class:
if we want the law to lead to efficient outcomes,
we can try to design the law to eliminate externalities!
22
Another thing that leads to inefficiency:
barriers to trade
 Cuban cigars




Suppose I’d pay $15 each for Cohibas
They cost $2 each to make
Clearly, it’s efficient for me to smoke Cohibas
But trade embargo on Cuba makes it illegal for me to buy them
 Anything that prevents me from buying something I want
can be a source of inefficiency


One approach to property law: make it as easy as possible for
people to trade among themselves
(This may seem like an obvious point; but then, there are lots of
things we’re not allowed to sell…)
23
And another: taxes
 I value my free time at $40/hour
 Working in a factory, I can build things worth $50/hour
 Clearly, it’s efficient for someone with a factory to hire me
 But if income tax is 25%, then it won’t happen


Factory owner can’t pay me more than $50/hour
I won’t accept less than $53.33/hour pre-tax
24
Another: monopoly (or private information)
 Example




Demand for some good
given by P = 100 – Q
Monopolist can produce
good for $40/unit
Monopoly price is 70,
demand is 30
Deadweight loss is
inefficiency

Customers willing to pay
more than marginal cost
but unable to trade
P* = 70
CS
Profit
P = 100 – Q
DWL
MC = 40
Q* = 30
25
But, saying these things lead to inefficiency
doesn’t automatically mean they’re bad
 For example


we just said taxes lead to inefficiency
but without taxes, there’s no way to fund public goods, and not
having public goods is also inefficient
 But also, we’ve defined “efficient”, but we haven’t claimed
that “efficient = good”
 Which brings us to…
26
Is efficiency a good
goal for the law?
27
Important distinction: positive versus
normative economics
 positive statements are statements of fact



“economics of what is”
can be descriptive: “in 2007, U.S. GDP was $13.8 trillion”
can be theoretical predictions: “if prices rise, demand will fall”
 normative statements contain value judgments



“economics of what ought to be”
for example, “less inequality is better”
or, “government should encourage innovation”
28
Most of this class will be positive
 Predicting behavior, and outcomes, that follow from a law
or legal system is positive analysis


“Law X will lead to more car accidents than law Y”
“Law X will lead to more efficient outcomes than law Y”
 But in the background, we’d like some sense of what is
the normative goal of the legal system

“Law X is better than law Y”
 Posner, and many others, argue that efficiency should
be that goal
29
Posner gives us one argument why the law
should aim to be efficient
 Richard Posner (1980), The Ethical and Political Basis of
Efficiency Norm in Common Law Adjudication
 Starts with the observation: if you buy a lottery ticket and
don’t win anything, you can’t complain
 Imagine before we all started driving, everyone in the
world got together and negotiated a liability rule for traffic
accidents
 If one rule is more efficient than another, we’d all vote for
that rule ex-ante – ex-ante consent
30
Things are a little more complicated…
 Even ex-ante, bad drivers might prefer a less efficient
system if it meant drivers weren’t responsible
 Posner deals with heterogeneity with a different example
 And of course, this consent is all hypothetical
 Posner’s basic argument: if we choose the most efficient
legal system, everyone is “compensated ex-ante” for the
choice, and should willingly accept the outcome they get
31
Posner’s argument does have its limitations…
 The “lottery ticket” analogy requires risk neutrality


50% chance at $1,000,000 is just as good as 50% chance at
$900,000 and 50% chance at $100,000
If $100,000 is “worth more to you” when you’re broke than when
you already have $900,000, this argument doesn’t work
 Counterpoint to Posner: Hammond (1982)



Efficiency is really a special case of utilitarianism, and subject to
the same limitations
“Value” = “willingness to pay”
$1 worth the same to everyone
32
This highlights some of the things efficiency
is not
 efficiency is not equity
 efficiency is not fairness
 efficiency is not maximizing happiness
“Suppose that pituitary extract is in very short supply… and is
therefore very expensive. A poor family has a child who will be a
dwarf if he doesn’t get some of the extract, but the family cannot
afford the price [or borrow the money].
A rich family has a child who will grow to normal height, but the
extract will add a few inches more, and his parents decide to buy it
for him.
In the sense of value used in this book, the pituitary extract is more
valuable to the rich family… because value is measured by
willingness to pay, but the extract would confer greater happiness in
the hands of the poor family.”
- Posner, Economic Analysis of Law
33
A more pragmatic defense of efficiency as a
goal for the law
 Cooter and Ulen (textbook ch. 1)
 Efficiency should not necessarily be the goal of society
 But efficiency should be the goal of the legal system
 If redistribution is desirable, it’s better to make the legal
system efficient, and address distribution through taxes

Cooter and Ulen offer four reasons why the tax system is a better
way to redistribute wealth than the legal system
34
Four reasons the tax system is a better way
to redistribute wealth than the legal system
1.
Taxes can target “rich” and “poor” more precisely than the
legal system can
2.
Distributional effects of legal changes are harder to
predict
3.
Lawyers are more expensive than accountants
4.
More narrowly-targeted taxes cause greater distortion
than broad-based taxes
35
So, summing up… is efficiency a good goal
for the law?
 We’ve seen two arguments in favor


Posner: it’s what we all would have agreed on ex-ante
C&U: if you want to redistribute, it’s better to do it through taxes
 But there are definitely some problems with efficiency

Distribution matters; not everything is monetizable; people might
care about procedural fairness
 My take


In this class, we’ll mostly focus on the positive questions
But in the background, I think of efficiency as a “pretty good”, but
definitely imperfect, measure of “goodness”
36
(Friedman has his own take on why we
should study efficiency)
“The central question [in this book]… is a simple one: what set of
rules and institutions maximize the size of the pie? What legal
rules are economically efficient?
There are at least three reasons why that is the question we ask.
The first is that while economic efficiency… is not the only thing
that matters to human beings, it is something that matters quite a
lot to most human beings.
The second reason is that there is evidence that considerable parts
of the legal system we live in can be explained as tools to generate
efficient outcomes… It is a lot easier to make sense out of a tool if
you know what it is designed to do.
A final reason is that figuring out what rules lead to… efficient
outcomes is one of the things economists know how to do –
and when you have a hammer, everything looks like a nail.”
- Friedman, Law’s Order, p. 312
37
Finally…
 One argument from C&U for why law should focus on
efficiency, redistribution should be done through taxes:
“narrow taxes cause more distortion than broad taxes”


Wednesday, we’ll work through an example of this
“Optional homework problem”
 If you want to read something for Wednesday:
Ronald Coase, “The Problem of Social Cost”
 See me if you’re not yet registered
That’s it for today – see you Wednesday
38