Post on 20-Dec-2015
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
2000 Camry,180K miles,
$5,000
180K
Main structures
• Trie of simple orders
• List of complex orders
Depth-first search
Model
Mileage
Year Year
CorvetteMustang
1996
50K
1996 Mustang,50K miles,
$7,000
Year
Camry
1999
Mileage
1999 Camry,10K miles,
$18,000
10K
Mileage
1988
1988 Corvette,20K miles,
$4,000
20K
Mileage
2000
2000 Camry,180K miles,
$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
1996 Mustang,50K miles,
$7,000
Year
Camry
1999
Mileage
1999 Camry,10K miles,
$18,000
10K
Mileage
1988
1988 Corvette,20K miles,
$4,000
20K
Mileage
2000
2000 Camry,180K miles,
$5,000
180K
Buy Order:Any car made
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.
2000 Camry180K miles, 4 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
1999 Camry10K miles, 6 cyl.
2000 Camry180K miles, 4 cyl.
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
20K 40K 60K 80KMiles
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
20K 40K 60K 80KMiles
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
20K 40K 60K 80KMiles
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
20K 40K 60K 80KMiles
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
20K 40K 60K 80KMiles
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
20K 40K 60K 80KMiles
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
2000 Camry,60K miles
60K
$3K
$7K
$9K
$10K
$12K
$14K
$15K
$17K
Buy Order:Any car made
after 1990
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
2000 Camry,60K miles
60K
$3K
$7K
$9K
$10K
$12K
$14K
$15K
$17K
Buy Order:Any car made
after 1990
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
2000 Camry,60K miles
60K
$3K
$7K
$9K
$10K
$12K
$14K
$15K
$17K
Buy Order:Any car made
after 1990
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
2000 Camry,60K miles
60K
$3K
$7K
$9K
$10K
$12K
$14K
$15K
$17K
Buy Order:Any car made
after 1990
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
2000 Camry,60K miles
60K
$3K
$7K
$9K
$10K
$12K
$14K
$15K
$17K
Buy Order:Any car made
after 1990
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
2000 Camry,60K miles
60K
$3K
$7K
$9K
$10K
$12K
$14K
$15K
$17K
Buy Order:Any car made
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