Econ 522
Economics of Law
Dan Quint
Spring 2012
Lecture 2
Logistics
 If you’re still trying to get into the class, get your name on
the yellow pad
 TA sections begin this Friday
 “Fake homework” for Wednesday on website
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Monday, we…
 defined law and economics
 saw some brief history of the common law
 and the civil law
 and discussed ownership of dead whales
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Today: efficiency
 what is efficiency?
 is efficiency a good goal for the law?
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What is
“efficiency”?
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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
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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
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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 seizes your car and gives it to me



I’m better off, you’re worse off
combined with me giving you $3,500, it’s 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

I’m $4,000 better off, you’re $3,000 worse off, $4,000 > $3,000
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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 $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)
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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
 a change in the economy is a Kaldor-Hicks improvement
if the winners’ gains outweigh the losers’ losses






if you have the party…
I’m $100 worse off
You’re $50 better off
30 guests are each $5 better off
– $100 + $50 + 30 X $5 = $100 > 0
Gains outweigh losses, so party is a Kaldor-Hicks improvement
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So…
 A Kaldor-Hicks improvement is any change that
“creates value…”
 …where value is equated with willingness to pay


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
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Efficiency
 we will call a change to the economy efficient if it is a
Kaldor-Hicks improvement
 we’ll say law A is more efficient than law B if moving from B
to A is a Kaldor-Hicks improvement
 and we’ll say a situation is efficient if there are no available
Kaldor-Hicks improvements


an efficient situation is when there’s no way to make some people
better off, without making some others worse off by more
we’re already getting maximal value out of all available resources
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Example: is it efficient for me to drive to work
instead of taking the bus?
 Bus to campus 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
 By driving to work, I create $11 of total costs
 It’s efficient for me to drive to work if the benefit I get is
more than $11

If the benefit is less than $11, it’s inefficient for me to drive
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Some other, similar measures
 our definition of efficiency: actions are taken when total
benefits outweigh total costs

“goal” is to achieve all Kaldor-Hicks improvements
 Ellickson: efficiency is “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’”
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What forces lead to
inefficiency
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To see whether something’s efficient…
 Compare gains to everyone in society (total social
benefit)…
 …to costs to everyone (total social costs)
 Example we already saw (me driving to work):



Total social cost = $1 (gas) + 1,000 X $0.01 = $11
Total social benefit = whatever I gain by driving to work
So we just said: it’s efficient for me to drive to campus whenever
the value I get from driving is more than $11
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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

so I’ll drive whenever benefit to me is more than $1
 On days when value I get from driving is more than $1 but
less than $11, I drive to work even though that’s
inefficient
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So externalities cause inefficiency
 I’ll do something whenever private benefit > private cost
 Efficiency depends on whether social benefit > social cost
 If I was the only one affected by my choices, then social
benefit = private benefit and social cost = private cost

when I’m deciding which movie to watch on Netflix, nobody else is
effected by my choice, so my choice 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
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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
So everyone ends up fishing
more than the efficient amount
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Tragedy of the Commons – example



20 fishermen
Cost of fishing is 8 fish per hour
Notation



Total fish
caught
H (260 – H)
Efficient
Level of
Fishing
h = how many hours I fish
H = combined hours everyone fishes
H = hours everyone but me fishes
“Maximum
Sustainable Yield”
“Equilibrium”
Level of
Fishing

Fishermen catch 260 – H fish per hour
(a)
What is the efficient level of fishing? How much utility does that
give to each fisherman?
6.3 hours per day per fisherman; 793.8 fish/day
Left to their own devices, how much will each person fish? How
much utility will each person get?
12 hours per day per fisherman; 144 fish/day
(b)
0
3
6
9
12
Hours fishing, per day, per fisherman
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What’s going on here?
 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
Aristotle: “That which is common to the greatest number has the
least care bestowed upon it”
Elinor Ostrom, who shared the 2009 Nobel Prize in Economics,
studies how different societies solve this problem
 Positive externalities work the opposite way

Activities which create positive externalities are naturally done less
than the efficient amount
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So externalities can lead to inefficiency
 Without some sort of regulation/intervention…


Activities which impose a negative externality will be done more
than the efficient amount…
…and activities which impose a positive externality will be done
less than the efficient amount
 One idea we’ll see several times in this class:
if we want the law to lead to efficient outcomes,
we can try to design the law to eliminate externalities!

“Internalization”
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Other forces which
lead to inefficiency
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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, and another
$3 each to transport from Cuba to Madison
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…)
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Another thing that leads to inefficiency:
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 me to work


Each hour I work creates $10 of new value
Doesn’t matter who gets it – it’s efficient for me to work
 But if income tax is 25%, then it won’t happen




Factory owner can’t pay me more than $50/hour
But $50/hour pre-tax is only $37.50 after-tax…
…and I’d rather stay home than earn $37.50 an hour
So I don’t get hired, which is inefficient
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Another example of taxes leading to
inefficiency
 This is a new BMW that’s been cut in half
 Taxes distort behavior away from efficiency
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Another thing that leads to inefficiency:
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
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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 be far too few public goods, which is
also inefficient
we just said monopoly leads to inefficiency…
…but we’ll study patents, which are legal monopolies used to get
companies to innovate
 But also, we’ve defined “efficient”, but we haven’t claimed
that “efficient = good”
 Which brings us to…
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Is efficiency a good
goal for the law?
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Important distinction: positive versus
normative economics
 positive statements are statements of fact



can be descriptive: “in 2007, U.S. GDP was $13.8 trillion”
can be theoretical predictions: “if prices rise, demand will fall”
“economics of what is”
 normative statements contain value judgments



for example, “less inequality is better”
or, “government should encourage innovation”
“economics of what ought to be”
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Most of this class will be positive analysis
 Predicting behavior, and outcomes, that follow from a law
or legal system is positive economics


“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”
 One candidate for that normative goal is efficiency
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Friedman gives a few arguments for
studying 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
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But…
 This answers the question, “Why is it interesting to study
efficiency?”
 Not the question, “Should the law be designed with the
goal of achieving efficiency?”
 To answer this latter question…
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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
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Ex-ante consent – simple example
 Suppose there are two candidate rules for accident liability
 One favors pedestrians, one favors drivers
 The one favoring car drivers is more efficient
Expected
Expected Expected payoff if you
payoff,
payoff,
don’t know which one
drivers
pedestrians
you’ll be
Strict liability rule
-100
0
-50
Negligence rule
-20
-60
-40
 Posner’s point: before we know who we’ll be, everyone
would unanimously agree to the second rule
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Things are a little more complicated…
 People without cars would prefer a less efficient system
if it meant drivers were responsible
 Posner deals with heterogeneity with a different example
 Landlord-friendly versus tenant-friendly laws




Might think tenants would prefer pro-tenant laws
But rents are determined competitively
If laws become more tenant-friendly, rents might go up to
compensate
And if tenant-friendly law is less efficient, it could make both
sides worse off!
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Example: new law requiring landlords to pay
for their tenants’ heat







Suppose tenants get $1000 value from apartment, minus rent
Landlords pay $100 for heat, $600 in other costs
Without this law, tenants would pay for their own heat
They’d heat apartment less, get $980 value and pay $60 for heat
Might think tenants would prefer inefficient tenant-friendly law…
But rents are set competitively, would go up to compensate…
So both landlords and tenants do better under the old law!
Landlord pays for heat
Tenant pays for heat
Tenants’
payoffs
Landlords’
payoffs
Tenants
Landlords
1000 – rent
rent – 600 – 100
1000 – 850
= 150
850 – 600 – 100
= 150
980 – 60 – rent
rent – 600
980 – 60 – 760
= 160
760 – 600
= 160
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Ex-ante consent, ex-ante compensation
 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
 Of course, all this consent is hypothetical…
 …and it does have certain limitations
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Limitations to Posner’s argument
 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
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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
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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
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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
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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”
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For Monday…
 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 ahead, look at
Ronald Coase, “The Problem of Social Cost”
(although we probably won’t get to Coase till Wednesday)
 See me if you’re not yet registered
That’s it for today – see you next week
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