Econ 522Economics of Law

Dan Quint

Spring 2012

Lecture 3

HW1 is online (due 11:59 p.m. Thurs Feb 9)Also lecture notes – try View Notes Page

Efficiency: “all available Kaldor-Hicks improvements made” roughly, maximizing total value, or total surplus, or total payoffs, to

everyone in society… …where everything is translated into dollars, so we’re able to

add/compare across people

Means that… each scarce resource is owned by whoever values it most goods are produced whenever their value is greater than their cost and so on

Last week, we defined efficiency

Externalities People make choices based on private cost and private benefit Efficiency is based on social cost and social benefit When social cost > private cost, negative externality

people will do something more than efficient amount When social benefit > private benefit, positive externality

people will do something less than efficient amount

Barriers to trade, taxes

Monopoly/private information

And we discussed some forces that lead to inefficiency

Posner: yes – ex-ante, we would all have agreed to efficient laws Analogy to lottery ticket with highest expected value Example for asymmetric situations (landlords and tenants)

Cooter & Ulen: yes – if we want to adjust the distribution of wealth, better to do it through tax system Several reasons taxes better than legal system for redistributing

wealth

And we asked: Should efficiency be the normative goal of the law?

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

Four reasons the tax system is a better way to redistribute wealth than the legal system

7

Two goods: beer (x), pizza (y)

One consumer, with $60 and utility u(x,y) = x0.5 y0.5

a. Given prices p for beer and q for pizza, calculate demand.

(x,y) = (30/p, 30/q)

Beer and pizza are produced at $1 per unit, and perfectly competitive markets

So without any taxes, p = q = $1

b. Calculate demand, and utility, with no tax.

(x,y) = (30, 30) u(x,y) = 300.5 300.5 = 30

c. Calculate demand and utility with $0.50 tax on beer.

(x,y) = (20, 30) u(x,y) = 200.5 300.5 = 6000.5 24.49

d. How much revenue does $0.50 tax on beer raise?

20 X $0.50 = $10

e. Calculate demand and utility with $0.20 tax on both goods.

(x,y) = (25, 25) u(x,y) = 250.5 250.5 = 25

f. How much revenue does $0.20 tax on both goods raise?

25 X $0.20 + 25 X $0.20 = $10

g. Which is the better way to raise revenue?

To make this last point, an example

Aside from maximizing efficiency, what are other plausible normative goals for a legal system?

When would you expect these goals to be in conflict with efficiency?

Discussion question

Let’s first dispense with the straw man. I’ve never heard of an economist who believes that every efficient policy is good, and I’ve heard of very few who believe that every inefficient policy is bad.

It’s true that most economists do seem to believe that any good policy analysis should start by considering efficiency. That doesn’t mean it should end there.

I think economists are right to emphasize efficiency, and I think so for (at least) two reasons. First, emphasizing efficiency forces us to concentrate on the most important problems. Second, emphasizing efficiency forces us to be honest about our goals.

– Steven Landsburg

http://www.thebigquestions.com/2010/08/30/efficiency-experts

A nice blog post about why policy evaluation should at least start with efficiency…

Politician: Here’s my program to make the health care system work better by subsidizing health care for the poor.

Economist: Your program costs a billion dollars and delivers half a billion dollars worth of benefits. That’s inefficient.

Politician: So what?

Economist: Well, the “so what” is that maybe you could take that billion dollars and deliver a full billion dollars worth of benefits instead if you spent it a little differently. Why not just hand the cash out to poor people?

Politician: Because I don’t want to help all poor people. I only want to help sick poor people – and this is the only way I can think of to do that.

Economist: Ah. So your goal here is not to make the health care system work better at all. Instead it’s to transfer resources to sick poor people.

Politician: I guess so.

Economist: That’s fine. Now we can have a healthy debate about whether that’s what we want to do.

“Emphasizing efficiency forces us to be honest about our goals”

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”

Summing up… is efficiency a good goal for the law?

12

I don’t have many “absolute beliefs” about economics Some people do

I hope that doesn’t make things too confusing

Before we move on, a quick digression…

13

I don’t have many “absolute beliefs” about economics Some people do

I hope that doesn’t make things too confusing

Relatedly, if I don’t see economics as a set of rules to memorize, how do I know what I know?

I need to see a model, or an example, that demonstrates it

Before we move on, a quick digression…

14

introduce some basic game theory

begin property law

Rest of today:

15

Some basicgame theory

16

Today, we focus on static games Also known as simultaneous-move games

A static game is completely described by three things: Who the players are What actions are available to each player What payoff each player will get, as a function of

his own action, and the actions of the other players

Any complete description of these three things fully characterizes a static game

A brief introduction to game theory

17

(Story)

Players: player 1 and player 2

Two actions available to each player: rat on the other, or keep mum

Payoffs: u1(mum, mum) = -1

u1(rat, mum) = 0

u1(mum, rat) = -10

u1(rat,rat) = -5

Same for player 2

A classic example: the Prisoner’s Dilemma

18

In two-player games with finite actions, one way to present game is payoff matrix

-1, -1 -10, 0

0, -10 -5, -5

Mum Rat

Mum

Rat

Player 2’s Action

Player 1’s Action

Player 1’s Payoff Player 2’s Payoff

Always Player 1

19

We solve a game by looking for a Nash equilibrium

Nash equilibrium is a strategy profile (an action for each player) such that: No player can improve his payoff by switching to a different action… …given what his opponent/opponents are doing

Nash Equilibrium

20

If any player can improvehis payoff by changing hisaction, given his opponents’actions, then it is not a Nashequilibrium

Is (Mum, Mum) an equilibrium? No, if player 2 is playing Mum

player 1 gains by deviating

A strategy profile is a Nash Equilibrium if no player can gain by deviating

-1, -1 -10, 0

0, -10 -5, -5

Mum Rat

Mum

Rat

Player 2’s Action

Pla

yer

1’s

Act

ion

21

My best response to a particular play by the other player is whichever action(s) give me the highest payoff

To find Nash Equilibria… Circle payoff from player 1’s

best response to each action by his opponent

Circle payoff from player 2’sbest response to each action

Any box with both payoffscircled is an equilibrium

Because each player is playinga best-response to his opponent’s action…

…so neither one can improve by changing his strategy

In two-player games, we find Nash equilibria by highlighting best responses

-1, -1 -10, 0

0, -10 -5, -5

Mum Rat

Mum

Rat

Player 2’s Action

Pla

yer

1’s

Act

ion

22

Another classic: Battle of the Sexes

(Story)

Circle player 1’sbest responses

Circle player 2’sbest responses

We find two equilibria: (ballgame, ballgame) and (opera, opera) Game theory usually doesn’t have that much to say about which

equilibrium will get played when there are more than one

Some games will have more than one equilibrium

6, 3 0, 0

0, 0 3, 6

Baseball Game Opera

BaseballGame

Opera

Player 2’s Action

Pla

yer

1’s

Act

ion

23

Growth model

(Story)

Circle player 1’sbest responses

Circle player 2’sbest responses

Two equilibria: (invest, invest)and (consume, consume) Some papers explain differences in growth across countries by

saying some are in “good” equilibrium and some are in “bad” one

Sometimes, there will be a “good” and a “bad” equilibrium

2, 2 0, 1

1, 0 1, 1

Invest Consume

Invest

Consume

Player 2’s Action

Pla

yer

1’s

Act

ion

24

Scissors, Paper, Rock for $1 Look for Nash

Equilibria by circling best responses

No square with both payoffs circled

No equilibrium where each player plays a single action

In this class, we’ll focus on games with a pure-strategyNash equilibrium

Some games don’t have any equilibrium where players only play one action

0, 0 1, -1

-1, 1 0, 0

Scissors Paper

Scissors

Paper

Player 2’s Action

Pla

yer

1’s

Act

ion -1, 1

1, -1

Rock

1, -1 -1, 1Rock 0, 0

25

Now on to…

That’s a very quick introduction to static games

26

Property Law

27

To begin, a story

28

We already saw one reason Tragedy of Commons – overuse of land is held in common

For another example, imagine two neighboring farmers

Each has two choices: farm his own land, or steal crops from his neighbor Stealing is less efficient than planting my own crops

Have to carry the crops from your land to mine Might drop some along the way Have to steal at night move slower

If I steal your crops, I avoid the effort of planting and watering

Why do we need property law in the first place?

29

Suppose that planting and watering costs 5, the crops either farmer could grow are worth 15, and stealing costs 3

With no legal system,the game has the following payoffs:

We look for equilibrium

Like Prisoner’s Dilemma both farmers stealing is the only equilibrium but that outcome is Pareto-dominated by both farmers farming

Why do we need property law in the first place?

10, 10 -5, 12

12, -5 0, 0

Farm Steal

Farm

Steal

Player 2

Pla

yer

1

30

Suppose there were lots of farmers facing this same problem

They come up with an idea: Institute some property rights And some type of government that would punish people who steal

Setting up the system would cost something Suppose it imposes a cost c on everyone who plays by the rules

So how do we fix the problem?

31

So how do we fix the problem?

10 – c, 10 – c -5 – c, 12 – P

12 – P, -5 – c -P, -P

Farm Steal

Farm

Steal

Player 2

Pla

yer

110, 10 -5, 12

12, -5 0, 0

Farm Steal

Farm

Steal

Player 2

Pla

yer

1

MODIFIED GAMEORIGINAL GAME

If P is big, and c is not too big, then 12 – P < 10 – c In that case, (Farm, Farm) is an equilibrium

Payoffs are (10 – c, 10 – c), instead of (0, 0) from before

32

Anarchy is inefficient I spend time and effort stealing from you You spend time and effort defending your property from thieves Instead of doing productive work

Establishing property rights, and a legal process for when they’re violated, is one way around the problem

So the idea here…

33

Cooter and Ulen: property is

“A bundle of legal rights over resources that the owner is free to exercise and whose exercise is protected from interference by others”

Property rights are not absolute Appendix to ch. 4 discusses different conceptions of property rights

Any system has to answer four fundamental questions: What things can be privately owned? What can (and can’t) an owner do with his property? How are property rights established? What remedies are given when property rights are violated?

Overview of Property Law

34

BUT…

Answers to many of these seem obvious

source: http://www.msnbc.msn.com/id/21088150/

35

Take a look at Coase, “The Problem of Social Cost”

See you Wednesday

Wednesday: Coase