Bargaining Theory Introduction

handshake

Bargaining Theory is a part of Game Theory. It helps us understand how people make deals when:

The final deal depends on what each person wants, how long they can wait, and what happens if they can't agree.

The Nash Bargaining Solution

Balance scale representing fairness

The Nash Bargaining Solution looks for a deal that:

The solution is found where the gains multiplied together reach the highest value.

We multiply gains because this gives the fairest balance: when both sides gain equally, the product is highest.

Example: Selling a Car

Sarah is selling her car.

  • The car is worth $2,000 to Sarah (she won't sell for less)
  • The car is worth $3,000 to Tom (he won't pay more)

There's an extra $1,000 of value between them! This is called the surplus.

  • If Tom pays $2,500, both gain $500
  • If Tom offers only $2,000, Sarah gains nothing extra
  • If Sarah demands $3,000, Tom gains nothing extra

The table below shows the "extra" value each person gets:

Final Sale Price Sarah's Gain
(Price − $2,000)
Tom's Gain
($3,000 − Price)
Nash Product
(Sarah × Tom)
$2,000 $0 $1,000 0
$2,250 $250 $750 187,500
$2,500 (Fair Deal) $500 $500 250,000 (MAX)
$2,750 $750 $250 187,500
$3,000 $1,000 $0 0

If they can't agree, they both get $0.

The Nash Bargaining Solution picks a split of (500, 500), where both sides gain equally.

Sharing the gains this way makes the deal strong and fair.

Working Together

Sometimes bargaining isn't just about splitting value, but about creating more of it first.

In Cooperative Bargaining, players find ways to grow the "total pie" before they cut it up.

A good cooperative deal has an important property:

This means the deal is good because no value is wasted.

Example: A Business Partnership

Two companies are thinking about working together.

WizardEd makes great apps. They have good tech but few sales staff.

School Gear sells school supplies. They know many schools but don't know how to make apps.

  • Alone, WizardEd earns $300,000
  • Alone, School Gear earns $200,000

Staying apart they earn a total of $500,000.

But if they team up:

  • WizardEd provides the software
  • School Gear sells it through its existing school network

Together, they can reach more customers and earn $700,000.

By working together, they made $200,000 of extra value.

Any deal where both companies get more than before is a win.

They just need to decide how to split that extra $200,000!

Cooperation often leads to better outcomes, but it requires trust, communication, and clear rules.

When Bargaining Fails

Not every talk ends in a deal. Sometimes people won't budge, and the whole thing falls apart.

When this happens, both sides fall back to what they get without an agreement, often much less.

Example: The Strike

A company and its workers' union negotiate wages.

  • If they agree, workers get paid and the company keeps operating
  • If talks fail, workers strike and production stops

During a strike:

  • The company loses money
  • The workers lose pay

No one wins.

Even a "bad" deal can be better than no deal at all.

Flexibility matters.

Rigid strategies can turn a possible win–win situation into a guaranteed lose–lose outcome.

Summary

Bargaining Theory shows that people with different goals can still reach agreements that benefit everyone, and that:

By understanding people's goals we can turn conflict into opportunity.