Exchanges for Complex Commodities: Toward a General-Purpose System

Exchanges for Complex Commodities:Toward a General-Purpose System

Committee:Eugene FinkRafael Perez

Dmitry B. Goldgof

John Hershberger

Motivation• Build an automated exchange for trading goods and services

• Combine the speed of the stock exchange with the flexibility of eBay

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Outline

• Previous work

• Previous work• One-attribute market

Outline

• Previous work• One-attribute market• Multi-attribute market

Outline

• Previous work• One-attribute market• Multi-attribute market• Large number of attributes

Outline

• Previous work• One-attribute market• Multi-attribute market• Large number of attributes• Numeric attributes

Outline

• Previous work• One-attribute market• Multi-attribute market• Large number of attributes• Numeric attributes• Complex orders

Outline

• Previous work• One-attribute market• Multi-attribute market• Large number of attributes• Numeric attributes• Complex orders• Price functions

Outline

• Previous work• One-attribute market• Multi-attribute market• Large number of attributes• Numeric attributes• Complex orders• Price functions• Main results

Outline

Combinatorial auctions

• Complex commodities

• Asymmetry between buyers and sellers

• Illiquid

Standardized exchanges

• Simple commodities

• Symmetry between buyers and sellers

• Liquid

One-attribute market

Price

Buy order

Stock symbol

$89.02

Price Sell order

Stock symbolGE IBM MCD GE IBM MCD

$89.00

One-attribute market

Price

Stock symbolGE IBM MCD

$89.02

Buy order

Sell order

$89.00

Table of items• Table of all tradable items

BA

GE

IBM

PG

MCD$88.94

$88.93 $88.97

$88.92 $88.93 $88.96 $88.99

• For each item, a tree of prices

Multi-attribute market

Mileage

Buy order

Model

Year

Mus

tang

50,000

00

03Mileage

Sell order

Model

Year30,000

0001

030202

01Ec

ho

Corv

ette

Cam

aro

Cam

ry

Echo

Mus

tang

Cam

ry

Cam

aro

Corv

ette

Multi-attribute market

Mileage

Model

Year

Mus

tang

50,000

00

0302

01Ec

ho

Cam

ry

30,000

Corv

ette

Cam

aro

Retrieval tree

Retrieval tree (a.k.a. trie) of simple orders

Year

1999

Year Year

1996 1988 2000

Camry

Model

CorvetteMustang

Mileage

1999 Camry,10K miles,

$18,000

10K

Mileage

50K

1996 Mustang,50K miles,

$7,000

Mileage

1988 Corvette,20K miles,

$4,000

20K

Mileage


$5,000

180K

Main structures

• Trie of simple orders

• List of complex orders

Depth-first search

Model

Mileage

Year Year

CorvetteMustang

1996

50K


$7,000

Year

Camry

1999

Mileage


$18,000

10K

Mileage

1988


$4,000

20K

Mileage

2000


$5,000

180K

Buy Order:Any car made

after 1990

Best price

Depth-first search With limited number of matches

Model

Mileage

Year Year

CorvetteMustang

1996

50K


$7,000

Year

Camry

1999

Mileage


$18,000

10K

Mileage

1988


$4,000

20K

Mileage

2000


$5,000

180K


after 1990

Best price amongfound matches

Actual best price

Limit: 2 matches

Large number of attributes

ModelCorvette

Year

Camry

1999

Mileage

10K

Mileage

2000

180K

Cylinders Cylinders

6 4

Mileage

Year

1996

50K

Cylinders

4

1996 Mustang50K miles, 4 cyl.

Year

Mileage

1988

20K

Cylinders

8

1988 Corvette20K miles, 8 cyl.

Mustang

1999 Camry10K miles, 6 cyl.


PATRICIA

Model

Year

Camry

1999,10K,

6

2000,180K,

4

1996 Mustang50K miles, 4 cyl.

1988 Corvette20K miles, 8 cyl.

Mustang, 1996,50K,

4



Corvette,1988,20K,

8

Numeric attributes

Mileage

Top speed

MPG

120 140

50,000

2322

21

Mileage

Sell order

Top speed

MPG30,000

Buy order

120 140

2322

21

Numeric attributes

Mileage

Top speed

MPG

120 140

50,000

2322

21

30,000

PATRICIA with numeric attributes

PATRICIA gives high branching factor

Mileage

100K,20, 110

10K miles, 25 MPG,

140 m.p.h.

100K miles,20 MPG,

110 m.p.h.

10K, 25,140

30K miles, 28 MPG,90 m.p.h.

90K,18, 100

90K miles, 18 MPG,

100 m.p.h.

30K,28, 90

KD-trees

Miles MPG

Car 1 50K 45

Car 3 70K 25

Car 4 90K 34

Car 5 30K 16

Car 6 40K 10

Car 2 20K 18

MP

G

50

0 100K20K 40K 60K 80K

10

20

30

40

(50,45)Car 1

(20,18)Car 2

(70,25)Car 3

(90,34)Car 4

(30,16)Car 5

(40,10)Car 6

Miles

Tree for handling numeric attributes

MP

G

50

10

20

30

40

(50,45)Car 1

(20,18)Car 2

(70,25)Car 3

(90,34)Car 4

(30,16)Car 5

(40,10)Car 6

Car 1

20K 40K 60K 80KMiles

KD-trees

0 100K

KD-trees

MP

G

50

10

20

30

40

(50,45)Car 1

(20,18)Car 2

(70,25)Car 3

(90,34)Car 4

(30,16)Car 5

(40,10)Car 6

Car 1

Car 2


0 100K

KD-trees

MP

G

50

10

20

30

40

(50,45)Car 1

(20,18)Car 2

(70,25)Car 3

(90,34)Car 4

(30,16)Car 5

(40,10)Car 6

Car 1

Car 2 Car 3


0 100K

KD-trees

MP

G

50

10

20

30

40

(50,45)Car 1

(20,18)Car 2

(70,25)Car 3

(90,34)Car 4

(30,16)Car 5

(40,10)Car 6

Car 1

Car 2 Car 3

Car 4


0 100K

KD-trees

MP

G

50

10

20

30

40

(50,45)Car 1

(20,18)Car 2

(70,25)Car 3

(90,34)Car 4

(30,16)Car 5

(40,10)Car 6

Car 1

Car 5

Car 2 Car 3

Car 4


0 100K

KD-trees

Car 1

Car 5

Car 2 Car 3

Car 4

Car 6

MP

G

50

10

20

30

40

(50,45)Car 1

(20,18)Car 2

(70,25)Car 3

(90,34)Car 4

(30,16)Car 5

(40,10)Car 6


0 100K

KD-trees

MP

G

50

10

20

30

40

(50,45)Car 1

(20,18)Car 2

(70,25)Car 3

(90,34)Car 4

(30,16)Car 5

(40,10)Car 6

Car 1

Car 5

Car 2 Car 3

Car 4

Car 6


0 100K

Complex orders

Mileage

MPG

Mileage

MPG

50,000

Sell order

50,000

25,000

Buy order

Top speed

120 140

Top speed

120 140

2322

21

2322

21

Complex orders

MPG

Mileage

50,000

25,000

Top speed

120 140

2322

21

Indexing of complex orders

Miles (K) MPG

Car 1 40–60 40–50

Car 3 52–88 20–30

Car 4 80–99 24–44

Car 5 25–35 11–21

Car 6 34–46 5–15

Car 2 12–28 13–23

Indexing of complex orders

MP

G

50

20K 40K 60K 80K

10

20

30

40

Car 1

Car 2

Car 3

Car 4

Car 5

Car 6

Miles

Car 1

Car 5

Car 2 Car 3

Car 4

Car 6

0 100K

Price functions

01

02

03

00

Year

Model

Price

Camaro Mustang Corvette

$32K

$30K

$28K

$28K

$30K

$32KPrice limit:$32K – (2003 – Year) · $2K

Order:2001-2003 Mustang

Price functions

01

02

03

00

Year

Model

Price

Camaro Mustang Corvette

$32K

$30K

$28K

$28K

$30K

$32K

Sell orderMustang made in 2003Price = $30,000

Buy order2001-2003 MustangPrice = $32K – (2003 – Year) · $2K

Price functions

• Orders with identical attributes are in the same leaf

• Each leaf includes a tree of prices

Leaf nodesModel

Mileage

Year Year

CorvetteMustang

1996

50K

1996 Mustang,50K miles

Year

Camry

1999

Mileage

1999 Camry,10K miles

10K

Mileage

1988

1988 Corvette,20K miles

20K

Mileage

2000


60K

$3K

$7K

$9K

$10K

$12K

$14K

$15K

$17K


after 1990

Leaf nodesModel

Mileage

Year Year

CorvetteMustang

1996

50K

1996 Mustang,50K miles

Year

Camry

1999

Mileage


10K

Mileage

1988

1988 Corvette,20K miles

20K

Mileage

2000


60K

$3K

$7K

$9K

$10K

$12K

$14K

$15K

$17K


after 1990

BestMatch

Main results

• Formalization of previous techniques

• Identification of open problems

• Theoretical solutions to some problems

Future work (Ph.D.)

• Advanced indexing structures

• Search for approximate matches

• Trading different commodity types in a common exchange

Exchanges for Complex Commodities: Toward a General-Purpose System

Documents

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