脱温暖化
2050

AIM/Material Stock and Flow Model

Reina Kawase
Kyoto University
19 October, 2006
AIM Training Workshop
National Institute for Environmental Studies, Tsukuba

1

Contents

1) Introduction2) Importance of estimation of material stock3) What is Material Stock and Flow Model ?
4) Description and Data
5) Methodology of developing the model6) Basic concepts and equations

2Current situation: Iron in Japan
With an increase of demands for goods, a lot of materials
have been accumulated as durable goods in the society.
1970
IMPORT：85
Scrap：11
Iron ore：68
Products：5

EXPORT：24

From EnvironmentIron ore：0.7
Sulfur iron：0.5308

To stock: 44

IMPORT：97
Scrap：6
Iron ore：81
Goods：10
From environment :123
Waste：19

Iron ore：12

Iron scrap

RECYCLE
Scrap：37

Durable goods

Scrap：0.2
Products：23

Total

2000

Depreciation
STOCKS
1

Total
input
137

Iron scrap

Stock change：5
Depreciation :40

Durable goods

Depreciation :1,290

Final disposal：18

To stock：58
Waste：14

RECYCLE :31

STOCKS:EXPORT：45
Scrap：6
Goods：39

Iron scrap： 20
Depreciation :Stock change：-1

Recycle：19

6
RECYCLERECYCLE

Unit：Mt

How will these stocks change in the future?
How will these stocks affect the society?
3Importance f Estimation of Stock
1.Estimation of Demand
Stocks affect the demand for goods. In the future, demand isgiven as a function of stock.
ex. Saturation with infrastructure and housing
The number of the car per person
Æ Material only for repair, maintenance, or rehabilitation isrequired.

Demand = f (Stock )2.Waste Generation
A large amount of materials accumulated in a society as durable
goods are expected to generate a large amount of wastes whengoods reach the end of their lifetimes.
4Importance f Estimation of Stock
3.Resource
The materials contained in stocks can be treated as resources.
Considering resource constraints, following points areimportant,a) what quantities of what materials will be needed in bothstocks and flows in order to fulfill final demand in the future?
b) how should these resources be most effectively used?

4.Relationship between Material Use and Energy
Consumption
Economic activities use many kinds of materials. Some law
material industries are energy-intensive. Under the LCS, how
the material is used? What influence dose the promotion ofmaterial recycling give the energy consumption ?

5

What is Material Stock and Flow Model?
Material stock and flow model (MSFM)* Estimates the change of material stocks and flow in thesociety.
* The factors considered in the model are•••••final consumption
investments which are affected by capital stocks
material densities of goods
physical input output coefficients of production sectors
recycling rate of wastes

Etc* Analyzes the mechanism of changes in material stocks andflow, and the effect of recycling materials in the futuresociety, and looks for the measures towards the LCS in
connection with material consumption.
6Statistics

population, the number of household, GDP, income, lifetime, import/export,
land use, production/stocks/inputs of durable goods, recycling，etc

Macroeconomic method
Relation between the factors
Demand＝ｆ(stock，price，dep.)
Material share＝f(time,,,)Scenario
Factors
Relation

Parameter
Material density (t/$)
Depreciation ratio
Recycling ratio

2000：Stocks(cohort)
Material flow

Scenario
Tech. inv
Consump.

Estimation of factors

EXO：future demand

INITIAL

PARAMETER

Goods / Material / Sector / Waste Balance，Technology function, Resource constraints, etc

Material Stock and Flow Model

Results
disposal

FDS

WST

MWS

Material Stocks/flows, waste, recycling, resource inputs
…

電気機
械輸送機
械精密機
械その他の製
造
工業
製品

INV

DurableGoods /Social
Capital

IMD

Goods
Dummy
Stock

鉄鋼
非鉄金属
金属製品
一般機械
電気機械
輸送機械
精密機械
その他の製造工業製
住宅建築（木造）住宅建築（非木造）
非住宅建築（木造）
非住宅建築（非木建築補修
公共工事
その他の土木建設

1,000,000

18,907
4
1,466
4,969
509
025
16,766 18,132
2381,247
678
430
725
2,198
745
0 13,661
75224650103
4541071
1773 1,317 4,256022
339 1,057 1,754
54
2159
1740
39
000000403
3800,000
600,000
400,000

木
造

住
宅
建
築
非木
造

非住
宅
建
築

非住
宅
建
築

その他の土
木
建
設

そ
… の他

87 3,663 874 5,818 3,528
0
3
23
16
84 3,617 2,846 2,872 2,129
6 195
6 142
68
555
16
41
35
0
00000
1
00001
3
96284032
7
110054

木
造

非木
造

建
築
補
修

公
共工
事

固定資
本形
成
量

最終
消費
量

81,2888253,21702580001

その他

200,000

32037
60001303743070

23636

74069311651

311336125

45

818220226251622
44
1,613
2,655
100
290

S 45

S50

S55

S 60
年

H 02

H07

H 12

産業産出量
単位:1000t

輸出量

財産出量

輸
入量

6 -80,919

013

39,892-3,647-11,199-2,141

359,771

23,890 10,124 31,176

638-628-37-574 -142-78

722 2,622 6,268 190 7,690 3,326 9,340 5,909

359,7717224,344
23,89010,124
31,176
638
722
2,622
6,268
190
7,690
3,326
9,340
5,909

1-8

532

-6,003

12
45,621-14,315-45,62136,172 -1,344 44,885 -97,322

477,956

24-2,897 -16,573
532

3,306

13

-5,824-14-574-1,447-1,208
-821
-165
-158

5,703
-920 -2,928 -109

100

-220 20,604
0
18
-130
865
-511 5,903
17 2,635-110 8,867
-8
180
2
80

702
11,778
2,993
4,483
325
179
2,622
6,268
190
7,690
9,340
5,909

環境からの投入
12
屑の投入
産業廃棄物量(除 屑) -250 -106
屑の発生

0120
在庫
純増
量

-365

2300132
03…

import

鉄のストック量( 1000t)

investment

HUS/GOV住宅建築）

一般機械）

final
consumption

SPY

Intermediate input

鉄鋼）

reuse

IMPT

農林水産業
鉱業

1,200,000

EXPT

FCS

ENV…

）

Production
Capital

鉱業

…

REU
OUT

農林
水産
業

1,400,000
exportSectorINP

財部門＼産業部門（depreciation

一般機械
精密機械
住宅建築（非木造）
公共工事

（DEP

金属製品
輸送機械
住宅建築（木造）
非住宅建築（非木造）（RCY

IWS / MWS

（パルプ・紙・木製品
電気機械
その他の製造工業製品
非住宅建築（木造）
その他の土木建設

waste generation

recycleRecycleVirgin80
60
40
20
02000 2005

2010

2015

2020 2025 2030 2035

2040 2045 2050

7Model description and Data
Description• Target Material
iron, wood, cement, aluminum• Time Horizon
2000-2050• Goods
ex. Iron (Building, Civil engineering structure, Machinery, Others)
Data•
••••
••Bench mark year:* Physical Input-Output date of each sector( * Input-Output table [monetary term] )Historical data: [for estimation of stock in a bench mark year]* Production statistic of each good
( * Investment of each good)8

Flow chart of MSFM
Macroeconomic ModelFinal
Consumption ofGoods

Investmentof Goods

InitialMaterial
StocksInvestment
Share of Material

Lifetime
Material Flow among
Domestic Sectors

Generated
Waste

BuildingDynamics
Model
Material Densityof Goods

Material
Demand for
Products

MaterialStocks

Import / Exportof Goods

Material Input for Construction
and Rehabilitation of Building
Physical Input Output
Coefficient for
Production

Material Import

RecycleExtraction fromthe Environment

Recycling
Rate
Waste

: Data flow
: Exogenous variable: Endogenous variable

Final Disposal
9

Development of the MSFM (1-1)
Step1: preparation of demand function
Methodology1: Input from other model
ex. Building dynamics model Æ Floor space of new dwellings

Iron for building = f (building type)=a1*( wooden)+ a 2*( steel framed )+ a3*( steel - reinforced concrete )+ a 4*( steel framed reinforced concrete structure)+ a5*(others )Tier1: Calculated by econometric method by using past data
Tier2: Assume constant value (ex. base year)10Development of the MSFM (1-2)
Step1: preparation of demand function
Methodology2: estimate/assume the function① pick up the variables which explain the car demand② find [assume] the relationship among the variables
TSP: language for the estimation andsimulation of econometric models

Car demand = f(income, driver ' s license ownership,
output of material production sec tors,?? )Year t:Car production (t) = Car demand(t) – Stocks of car(t)More information for TSP:

http://www.tspintl.com/

11

Development of the MSFM (2)Step2: Initial value of stocks
Tier1: you have physical data past several decades
Civil eng. structures.

100

2,000

80

1,600

60

1,200

40

800

20400

Machineries

Furniture

1940

1980

Steel stocks (Mil. ton)

Steel inputs (Mil. ton)

Buildings

01920

1940

1960

1980

200001920

1960

2000

Tier2: you have ONLY monetary data or few physical data
Base year : Physical stock [ton] = material density*(Capital stock [$])
material density (ton/$) : material per unit monetary amount
Assumption or rough estimation
12

Basic equation of MSFM (1)<Basic concept of calculation of material flow>
Material balance ( Goods / Sector / Waste )Production function (Goods / Waste)
Stock / Depreciation<Stock>Physical datamaterial density*monetary data

∑ STCK (i, m, t ) =∑ {STCK (i, m, t − 1) − DEP ( i, m, t ) + INV ( i, m, t )}DEP ( i, m, t ) = ∑ INV (i, m,τ ) * pdf (i, t ,τ )
τ ≤ t −1

* Ex. Normal distribution function* Estimate the function by historical data

Example of pdf(t)%0lifetime13

Material flow in the society
disposal

FDS

WST

MWS

waste generation

recycleRCY

IWS / MWS
DEP

depreciation

exportSectorINP

ENV

Production
Capital

REU
OUT

EXPT
final
consumption

reuse

FCS
SPY
investment

INV

HUS/GOV
DurableGoods /
SocialCapitalimport

IMPT

IMD

Goods
Dummy

Intermediate input

Stock14Material Flow: Iron
Iron ore

ExportProcess
Casting
Forging
Molding

ExportCastings
Limestone
Coke
Pellets

Blast
furnaceSteel import

CarSlag

Pig
iron

L.D.
converter

Ship
Steel
Crude
steel
Crude
steel

Domestic
scrapElectric

SemifinishedSlabBilletColdfinishedsteelHotrolledproducts

Ordinary
steel

Machinery

Steel

Building

Specialsteel

Home electric
appliance
Civilengineering
Container
Secondaryproducts

furnaceIronmaterial

Products

Slag
Steelexport

15

Basic equation of MSFM (2)<Goods Balance>

Production+ Import + Reuse= Total Spply =Intermediate+ Final Consumption+ Investment + Export
disposalFDS

WST

MWS

waste generation

recycleRCY

IWS / MWS
DEP

depreciation

exportSector<Sector Balance>

INP

ENV

Production
Capital

REU
OUT

EXPT

reuse

FCS

finalconsumption

SPY
investment

Intermediate+ Re cycle+ Environment

INV

HUS/GOV
DurableGoods /Social
CapitalimportIMPT

IMD

Goods= Total Input =Production* aji + Industrial Waste + Municipal Waste + Strage

Dummy

16

Basic equation of MSFM (3)<Production>

Fix?
Function of time by tech. growth?

Output = (1 + tech) ⋅ Total input<Waste generation>

IWS / MWS

Sector
INP

Production
CapitalOUTProduction process: Waste = (1 + tech) ⋅ Output
Final demand sector: Waste = a (t ) ⋅ Consumption
If you assume that “Technology parameter” changes depending on time,,,,,,
1) estimate by using historical data Å TSP
2) assume the figure
17Expected results¾Where, What kinds of, and how much of materials areaccumulated in the society?
¾Material flow among the sectors¾What kinds of and how much of wastes are generated?
¾How much of material is recycled?
After linking the material consumption and energy consumption,
analyze¾The relationship between the material use and energy
consumption[CO2 emission]¾Possibility or limitation of contribution of material flow change todevelop LCS.
18

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