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HW3 due Friday (5 p.m.)
Second midterm next Wednesday (November 10) Covers property and contract law – no torts
Logistics
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Efficiency Maximizing total surplus realized by everyone in society Scarce resources are owned by whoever values them most Actions are taken if social benefit exceeds social cost
Design a legal system that leads to efficient outcomes Once we set up the rules, we don’t expect people to act based on
what’s efficient We expect people to do whatever’s in their own best interest So the goal is set up the rules such that people acting in their
own best interest will naturally lead to efficiency
Our story so far
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Coase gives us one way to do that If property rights are clearly defined and tradable, and there are
no transaction costs, people have incentive to trade until each resource is efficiently owned
So initial allocation of rights doesn’t matter for efficiency But if there are transaction costs, we may not get efficiency this way
Led us to two normative views of the legal system: 1. Minimize transaction costs (“lubricate” private exchange) 2. Allocate rights as efficiently as possible
Tradeoff between injunctive relief and damages
Our story so far
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Property law works well for simultaneous trade
Contracts allow for non-simultaneous trade
Contract law can… Enable cooperation Encourage efficient disclosure of information Secure optimal commitment to performance Secure efficient reliance Supply efficient default rules and regulations Foster enduring relationships
Our story so far
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So far, we’ve been talking about voluntary exchange Coase is predicated on exchange being voluntary for both parties Contracts are an extension of voluntary trade
Up next: involuntary trade You’re bicycling to class, I’m texting while driving and I hit you You didn’t want to deal with me, I didn’t want to deal with you…
Our story so far
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To put it another way…
Property law covers situations where transaction costs are low enough to get agreement ahead of time Exceptions to property law – private necessity, eminent domain – when
this isn’t the case
Contract law covers situations when transaction costs are low enough for us to agree to a contract, high enough that we may not want to renegotiate the contract later
Tort law covers situations where transaction costs are too high to agree to anything in advance
Our story so far
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Tort, noun. from French word meaning injury
Contract law: situations where someone harms you by breaking a promise they had made
Tort law: situations where someone harms you without having made any promises
“If someone shoots you, you call a cop. If he runs his car into yours, you call a lawyer.”
Tort law
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I hit you with my car, do $1,000 worth of damage You’re $1,000 worse off (No damage to me or my car) Should I have to pay you damages?
As always, we’ll be focused on achieving efficiency
–1,000–1,000–1,000Combined payoffs
–50,000–1,0000My payoff
49,0000–1,000Your payoff
I owe $50,000I owe $1,000I owe nothing
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Question: how to structure the law to get people to behave in a way that leads to efficient outcomes?
Deliberate harms: make punishment severe (criminal law)
Accidental harms: trickier Goal isn’t “no accidents”; goal is “efficient number of accidents”
Tort law
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Question: how to structure the law to get people to behave in a way that leads to efficient outcomes?
Deliberate harms: make punishment severe (criminal law)
Accidental harms: trickier Goal isn’t “no accidents”; goal is “efficient number of accidents”
Unlike nuisance law, injunctive relief is not an option
Unlike contract law, no agreement ahead of time
Cooter and Ulen: essence of tort law is “the attempt to make injurers internalize the externalities they cause, in situations where transaction costs are too high to do this through property or contract rights”
Tort law
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Plaintiff – person who brings a lawsuit
Defendant – person who is being sued
In a nuisance case, the defendant caused a nuisance, plaintiff was bothered by it, might be asking for injunction or damages
In a contract case, defendant breached a contract or violated its terms
In a tort case, defendant caused some harm to plaintiff, plaintiff is asking for damages
Plaintiff is the victim (person who was harmed)
Defendant is the injurer (person who caused the harm)
Cast of characters
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For a tort to exist, the plaintiff needs to have been harmed
“Without harm, there is no tort” Gas company sold gas with a defective additive
Dangerous for cars with turbocharged carburetors You have a car with normal carburetors You might be angry; but you weren’t harmed, so you can’t sue
Similarly, no compensation for exposure to risk Manufacturer exposed workers to some chemical Exposure will cause 15% of them to develop cancer later in life Can’t sue now – have to wait, see who gets cancer, then they can sue
Element 1: Harm
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Element 1: Harm
Money
Health
Perfect compensation restores victim to original level of well-being generally done through money damages
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Perfect Compensation
• Emotional harm• Pain and suffering• Loss of companionship
• Medical costs• Lost income• Damaged property
Intangible harmsTangible harms
In theory, perfect compensation should cover all losses Historically, courts have been less willing to compensate for intangible or
hard-to-measure losses Over time, U.S. courts have started compensating for more intangible harms Pro: the closer liability is to actual harm done, the better the incentive to avoid
these harms Con: disparity in award sizes, unpredictability
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For a tort to exist, the defendant needs to have caused the harm to the plaintiff
Cause-in-fact “But for the defendant’s actions, would the harm have occurred?”
Element 2: Causation
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For a tort to exist, the defendant needs to have caused the harm to the plaintiff
Cause-in-fact “But for the defendant’s actions, would the harm have occurred?”
Proximate cause Immediate cause – defendant’s action can’t be too distant from the harm Palsgraf v Long Island Railway (NY Ct Appeals, 1928):
Guard pushed a passenger to help him onto train, passenger dropped fireworks he was carrying, they went off, explosion knocked down scales at the other end of the platform, which fell on Mrs. Palsgraf
Guard’s actions were not the proximate cause
Element 2: Causation
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“A tree fell on a moving trolly, injuring passengers. One of them sued.
He succeeded in demonstrating that in order for the trolly to be where it was when the tree fell on it the driver had to have driven faster than the speed limit at some point during the trip.
Breaking the law is per se negligence, so the driver was legally negligent whether or not his driving was actually unsafe.
If he had not driven over the speed limit, the trolly would not have been under the tree when it fell, so, the plaintiff argued, the driver’s negligence caused the injury.”
Court ruled driver’s negligence “had not caused the accident in the legally relevant sense”
Element 2: Causation
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Element 3: Breach of Duty
• Harm• Causation• Breach of duty (fault)
• Harm• Causation
NegligenceStrict Liability
When someone breaches a duty he owes to the defendant, and this leads to the harm, the injurer is at fault, or negligent Injurers owe victims the duty of due care Negligence rule: I’m only liable if I failed to take the required
standard of care – not if I was careful and the accident happened anyway
(Sometimes required, sometimes not)
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“A tree fell on a moving trolly, injuring passengers. One of them sued.
He succeeded in demonstrating that in order for the trolly to be where it was when the tree fell on it the driver had to have driven faster than the speed limit at some point during the trip.
Breaking the law is per se negligence, so the driver was legally negligent whether or not his driving was actually unsafe.
If he had not driven over the speed limit, the trolly would not have been under the tree when it fell, so, the plaintiff argued,the driver’s negligence caused the injury.”
Hence the language in the trolly example
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If I breach my duty of due care and injure you, I am liable
If I exercise the appropriate level of care but still injure you, I’m not liable
How is the standard of care determined? That is, how careful do I have to be to avoid liability, and who
decides? Is it negligent to drive 40 MPH on a particular road at a particular
time of day? What about 41 MPH? 42?
So under a negligence rule…
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Some settings: government imposes safety regulations that set standard for negligence Speed limits for highway driving Requirement that bicycles have brakes Workplace regulations
Some standards are left vague “Reckless driving” may depend on road, time of day, weather… Common law focuses on duty of reasonable care Level of care a reasonable person would have taken (Civil law relies less on “reasonableness” tests, tries to spell out what
level of care is required)
How is the standard of care determined?
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Strict liability rule: plaintiff must prove harm and causation
Negligence rule: must prove harm, causation, and negligence
A little history Early Europe: strict liability was usual rule By early 1900s, negligence became usual rule Second half of 1900s, strict liability became more common again,
especially for manufacturer liability in American consumer products U.S. manufacturers now held liable for harms caused by defective
products, whether or not they were at fault
Strict liability versus negligence
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The more carefully I drive, the less likely I am to hit you But, driving more carefully is also more costly to me Must be some efficient level of care
Similarly… Construction company can reduce accidents with better safety
equipment, better training, working shorter days, all of which cost money
Manufacturer can reduce accidents by designing/inspecting products more carefully – again, more expensive
Precaution
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Lots of things both victims and injurers can do to reduce number (or harm) of accidents
study warning on medicine
improve warning on medicine
medicine causes side effects
handle bottles carefullyimprove quality control by bottler
exploding coke bottle
back up data at riskbetter design of softwaresoftware fails
walk more safelydrive more safelycar hits pedestrian
park car in safer spacedrive more safelymoving car hits parked car
fireproof housemanufacture wiring more carefully
faulty electrical wiring causes house fire
Victim’s PrecautionInjurer’s PrecautionAccident
Cooter and Ulen, p. 338
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Precaution: anything either injurer or victim could do to reduce likelihood of an accident (or damage done)
The next two questions should be obvious…
How much precaution do we want? What is efficient level of precaution?
How do we design the law to get it?
We will call all these things precaution
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Car hits a bicycle In real life: driver probably has insurance In real life: some damage to bicycle, some damage to driver’s car In real life: driver and bicyclist may not even know what the law is
We’ll simplify things a lot, by assuming… Only one party is harmed Parties know the law, don’t have insurance (for now) We’ll focus on one party’s precaution at a time
To answer these questions, we’ll introduce a very simple model of accidents
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Unilateral harm – just one victim
Precaution – costly actions that make accident less likely Could be taken by either victim or injurer We’ll focus on one at a time
Notation x – the amount of precaution that is taken w – the cost of each “unit” of precaution
so total cost of precaution is wx p(x) – probability of an accident, given precaution x
p is decreasing in x A – cost of accident (to victim)
so expected cost of accidents is p(x) A
Model of unilateral harmx level of precautionw marginal cost of precautionp(x) probability of an accidentA cost of an accident
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Model of unilateral harmx level of precautionw marginal cost of precautionp(x) probability of an accidentA cost of an accident
Precaution (x)
$
p(x) A (Cost of Accidents)
wx (Cost of Precaution)
wx + p(x) A(Total Social Cost)
x* (Efficient Level of Precaution)
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efficient precaution: minx { wx + p(x) A }
w + p’(x) A = 0
w = – p’(x) A
Under reasonable assumptions (p(x) convex)… x < x* w < – p’(x) A
MSC < MSB more precaution efficient x > x* w > – p’(x) A
MSC > MSB less precaution efficient x = x* MSC = MSB
Model of unilateral harmx level of precautionw marginal cost of precautionp(x) probability of an accidentA cost of an accident
marginal social cost of precaution
marginal social benefit of precaution
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Model of unilateral harmx level of precautionw marginal cost of precautionp(x) probability of an accidentA cost of an accident
x
$
p(x) A
wx
wx + p(x) A
x*x < x* x > x*
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We haven’t yet said who is taking precaution
Some situations, only injurer can reduce accidents
Some situations, victim can too
Bilateral precaution is a little bit tricky, but if we look at the two parties one at a time, everything works fine
Wednesday: consider effect of different liability rules on precaution
Model of unilateral harm
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Three rules we’ll consider:
No liability
Strict liability
Negligence
Effect of liability rules on precaution
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In a world with no liability… Victim bears the cost of any accidents, plus the cost of any
precaution he takes Injurer bears cost of any precaution he takes, does not have to pay
for accidents
Rule 1: No Liability
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Rule 1: No LiabilityInjurer precaution
x
$
p(x) A
wx
wx + p(x) A
x*
Injurer’s private cost is just wx Injurer minimizes private cost by setting x = 0
Private cost to injurer
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Rule 1: No LiabilityVictim precaution
x
$
p(x) A
wx
wx + p(x) A
x*
Victim’s private cost is wx + p(x) A To minimize this, victim takes efficient level of precaution
Private cost to victim
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So in a world with no liability…
Injurer takes inefficiently low level of precaution (zero, or minimal amount)
Victim takes efficient amount of precaution
Rule 1: No Liability
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Perfect compensation: damages D = A
Under strict liability… Injurer pays damages for any accidents he causes So injurer bears cost of accidents, plus his own precaution Victim pays only for his precaution
Rule 2: Strict Liability
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Rule 2: Strict LiabilityInjurer precaution
x
$
p(x) A
wx
wx + p(x) A
x*
Injurer’s private cost is wx + p(x) A Injurer minimizes this by taking efficient level of precaution
Private cost to injurer
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Rule 2: Strict LiabilityVictim precaution
x
$
p(x) A
wx
wx + p(x) A
x*
Victim’s private cost is wx No incentive to take any precaution, victim sets x = 0
Private cost to victim
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Effect of liability rules on precaution
EfficientZeroStrict Liability
ZeroEfficientNo Liability
Injurerprecaution
Victimprecaution
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When it’s the injurer who can take precautions, a rule of strict liability is more efficient
When it’s the victim who can take precautions, a rule of no liability is more efficient
Each rule works well for one incentive, poorly for other Similar to paradox of compensation we saw in contract law Negligence rule may allow us to get both incentives right
So for accidents with unilateral precaution…
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“Simple Negligence” rule
Legal standard of care xn
Injurer is liable for damages if precaution level was below the legal standard of care x < xn D = A x xn D = 0
So on our graph from before, private cost to injurer is… wx + p(x) A for x < xn
wx for x xn
Rule 3: Simple Negligence
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Rule 3: Simple NegligenceInjurer precaution
x
$
p(x) A
wx
wx + p(x) A
xn = x* Private cost is wx + p(x) A if x < xn, only wx otherwise If standard of care is set efficiently (xn = x*), injurer minimizes private cost by taking efficient precaution
Private cost to injurer
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Rule 3: Simple NegligenceVictim precaution
$
p(x) A
wx
wx + p(x) A
x*
What about victim? We just said, injurer will
take efficient precaution Which means injurer will
not be liable So victim bears costs of
any accidents (Victim bears residual
risk) So victim’s private cost is
wx + p(x) A Victim minimizes private
cost by taking efficient level of precaution too!
Private cost to victim
(assuming injurer takes efficient level of precaution
and is therefore not liable for damages)