demonstration of capabilities of a bi- regional cge model to assess impacts of rural development...
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Demonstration of capabilities of a bi-regional CGE model to assess impacts of rural development policies (RURMOD-E)
Demonstration WorkshopBrussels, 26.11.2008
THE BI-REGIONAL CGE MODEL:
CHARACTERISTICS AND
APPLICATION
Demetrios Psaltopoulos
Department of Economics
University of Patras
SAM & General Equilibrium models Major Part of TERA (FP6 – CT6469) project This Presentation deals with Aim (motivation), characteristics and implementation
StructureBackground Modelling Approach SAMs and CGE ModelsModel Structure Application
Introduction
Background
TERA: Economic development in remote rural areas
Aims:Role territorial factors which influence developmentreview whether existing policies take account of factorspropose new policy interventions.
“The trends and choices that affect rural areas cannot be studied in isolation from what is going on in non-rural areas” (Saraceno, 1994)
Approach Regional/Local Modelling within region rural-urban linkages
6 Case Study areas. Reflect different
Economic and Institutional Context Spatial Scale Rural-urban relationships
d
OECD Rural Classification:Nuts 3
The Bi-Regional CGE Model IFPRI CGE model (Lofgren et al., 2002):
sufficiently flexible to accommodate a fairly wide range of views on how regional economies adjust to specified policy shocks.
Modifications to allow specific characteristics of the study areas and moreover RURAL-URBAN INTERACTIONS such as:
a) the differentiation of rural and urban production sectors, factors and households
b) several specific characteristics of the regional economies under analysis.
The Modeling Framework
The Bi-Regional SAM The Bi-Regional SAM provides the base year values
which, in conjunction with other data (e.g. physical quantities, elasticities), are used to calibrate the CGE model.
Rural/ Urban Regions
Model Accounts Production Activities Commodities Factors of Production Households Other Institutions (G, ROW) Objective: Define accounts allowing analysis of R-U
questions.
The Modeling Framework
Key Elements
Remoteness and Distance
Spatial Disaggregation - production activities, factors and households
No Spatial Disaggregation - Commodities- Theoretical (Market Integration)- Practical (Data Collection)
Explicit transport sector – Data Collection – Policy Analysis
Factor Mobility - Spatial Disaggregation of certain
factors
The Modeling Framework
Social Accounting Matrix
Exhaustive Accounting all Flows in Regional Economy
Starting Point for CGE – Base Year
Empirical Applications - Other Data needed
Physical Quantities, e.g. sectoral employment, elasticities
Each SAM Account – Row and column
Row entries = payment from column account to row account.
The Modeling Framework
Example SAM Accounts Definitions
Production Activities Agricultural Rural Manufacturing Rural Manufacturing Urban Transport Services
Commodities Agricultural Manufacturing Transport Services
The Modeling Framework
Example SAM Accounts Definitions cont
Factors Unskilled Labour Rural Skilled Labour Rural Unskilled Labour Urban Skilled Labour Urban Capital Land Housing Rural Land Agricultural Rural
Land Housing Urban
The Modeling Framework
Households Rural Commuter Rural Other Urban
Other Institutions Direct Income Tax Collection Indirect Activity Tax Collection Indirect Sales Tax Collection Government Rest Of The World Savings-Investment
The Modeling Framework
Computable Equilibrium Model (CGE)
Behaviour of representative agents in economy Producers and Traders – maximise profits Consumers – maximise their well-being (have demand curves) Government collects taxes and makes transfers (tax rates and
transfers are exogenously set)
Model Closure rules – assumptions on how markets operate e.g. labour (study-area-dependent)
All transactions in “economy” accounted for.
TERA-CGE Models IFPRI Standard CGE Model (Lofgren et al., 2002)
(www.ifpri.org/pubs/microcom/micro5.htm)
The Modeling Framework
Production structure
Commodities
Set a activities, c commodities, f factors, h households.
Production Behaviour Each activity profit maximising firm
Activity Production Function (Cobb Douglas)
Factor Demand (PMAX conditions)
Intermediate Demand
Demand commodity c = constant*activity level a (i-o)
Domestic Commodity Output
Output commodity c = Sum over Activities ( constant*activity level a)
(Activities produce commodities in fixed proportions)
Commodities
Armington Assumptions – to prevent over-specialization
Imports/Exports/Domestic Commodities Imperfect Substitutes
Exogenous Import & Export Elasticity Required for each Commodity
Sales Tax Charged on Composite Commodity - Fixed rate derived from SAM
Households
Income Receive income - factors, transfers from Govt & ROW
Income from factor f = fixed share of factor return*wage* factor supply
Fixed Factor Shares derived from SAMExpenditure
Households pay income tax, save given proportion of income and demand commodities & demand housing services
Income Tax Rate, mps, Demand Shares derived from SAM
GovernmentExogenous Demand for Commodities, Transfers, receives indirect and income taxes
Investment DemandFixed shares across commodities consistent with SAM
How we construct a Regional CGE Model?
1. Construction of the SAM Table Carefully scrutinize the structure and characteristics of
the regional economy, Taking in mind the objectives of each study into
account and the problem(s) this leads into the definition of the structure of the SAM accounts,
Necessary regional information on the SAM accounts (I/O table, factor payments, household income, government spending-receipts, institutional income distribution and transfer payments)
Application of I/O regionalization techniques (such as GRIT)
Regional Application
Regional Application2. Parameterization Specification of elasticity coefficients (trade, production,
household elasticities) which quantify how production, consumption, etc. adjust to altered economic conditions,
Calibration of the CGE model: the values of the normalizing parameters replicate the flow values observed in the SAM.
3. Macroeconomic Assumptions (Closure Rules) Neoclassical: prices adjust and supplies are fixed, Keynesian: prices are fixed and supplies vary
Regional CGE Models and Policy Analysis CGE models are a very useful tool for rural policy
analysis due to their micro/non linear nature, CGE models capture a wide range of RD policy
effects:
a) short run (construction process)
b) long-run effects of new business activity (supply- or demand-driven)
c) secondary effects based on the migration, commuting and trade patterns of households.
CGE models can be used for carrying out a series of policy-related shocks (e.g. CAP reform, income transfers, population inflows) based on hypotheses
However there are some shortcomings: Numerous hypotheses and objective judgements
utilized for the parameterization of the model, The black-box criticism “models such as this one
often have lurking within them several key driving forces that originate in their SAM data base, algebraic structure and parameter assumptions, but whose influence on the model results remain hidden and open to misattribution” (Wing, 2005).
Limited applicability of single-region models at the small area level
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