RunDynam

Recursive Dynamic Model - RunDynam
Fact Sheet

Source: Commission modelling inventory and knowledge management system (MIDAS)

Date of Report Generation: Mon Apr 22 2024

Dissemination: Public

© European Union, 2024

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Overview

Acronym

RunDynam

Full title

Recursive Dynamic Model - RunDynam

Main purpose

A general equilibrium model used to analyse international trade policies scenarios.

Summary

Together with the GTAP database, Rundynam can be used to simulate different trade policy scenarios for more than 140 countries/regions and for around 65 sectors (agriculture, food, manufacturing and services).These tools allow to evaluate the impact in terms of export, import, GDP and sectoral output.

Rundynam is a model developed in the Center for Global Trade Analysis, at the Purdue University. It is a global network of researchers and policymakers conducting quantitative analysis of international policy issues. It also develops collaboration among academia, public sector and private sectors worldwide.

The use of economic models, like RunDynam, helps policy making with an economic theoretically consistent framework for analyzing trade policy questions. These types of models help to answer 'what if…' questions by simulating the price, income and substitution effects of different policy changes and comparing them to a so-called baseline (i.e., what would happen without a policy change). The baseline is key as it is the counterfactual against which the economic outcome of the initiative is assessed. Hence, CGE models allow economists to simulate, at the same time, how all sectors and actors adjust to the changes to costs, prices and/or incentives that a trade policy change would cause. This allows for an ex-ante assessment of all the direct and indirect effects of changes to trade policy. Usually, model results regard change in GDP, import and export flows, sectoral output, resources reallocation and price effect.

RunDynam, and similar models, are widely applied for providing the economic impact assessment of a trade policy agreement. The main advantage of CGE models is that they analyse the effects of trade policy taking into account the main links between the domestic and international production of goods and services.

Model categories

Economy

Model keywords

CGE

Model homepage

Ownership and Licence

Ownership

Co-ownership (EU & third parties)

Ownership details

Based on GTAP Data Base (Purdue University, USA) and GEMPACKcode (Centre of Policy Studies, Victoria University, Australia).

Licence type

Non-Free Software licence

The license has one or more of the following restrictions: it prohibits creation of derivative works; it prohibits commercial use; it obliges to share the licensed or derivative works on the same conditions.

Details

Structure and approach

RunDynam is a recursively dynamic applied general equilibrium model of the world economy and is built upon the Social Accounting Matrices (SAMs) of individual countries and regions. This model extends the comparative static framework of the standard GTAP model developed by Hertel (1997)  to a dynamic framework by incorporating international capital mobility and capital accumulation, while preserving all the features of the standard GTAP, such as constant returns to production technology, perfectly competitive markets and product differentiation by countries of origin – the so-called Armington assumption. RunDynam allows constructing a baseline (which may be a forecast) and policy deviations from the baseline. Users can view the results of the base case or policy deviation on the screen or export them to other programs. The model allows to simulate trade measure change, like tariffs cuts, in order to analyze the possible trade creation and trade deviation.

RunDynam relies on the Global Trade Analysis Project (GTAP). GTAP is a global network of researchers and policy makers conducting quantitative analysis of international policy issues. GTAP's goal is to improve the quality of quantitative analysis of global economic issues within an economy-wide framework. The GTAP network provides a global data base describing bilateral trade patterns, production, consumption and intermediate use of commodities and services. The latest version of the database, V10, refers to 2014 as reference year and covers 141 regions and 65 sectors (https://www.jgea.org/resources/jgea/ojs/index.php/jgea/article/view/77).

Input and parametrization

The impact of a trade policy shock cannot be evaluated without a baseline i.e. the counterfactual situation in which the economy would have been should there have been no trade policy change. Creating a realistic baseline is as difficult as it is important. The Commission usually relies upon predictions about the future by others, such as short term projections on GDP growth from the IMF and longer term projections on e.g. population from the UN, but also on energy consumption, labour participation rates, etc.

Main output

Output comes in the form of results on a wide range of indicators such as: (i) GDP or welfare (equivalent variation); (ii) Impact by sector in terms of exports, imports, production and value added reflecting  inter -sectoral input -output links including sourcing of inputs (goods and services) from abroad; (iii) Impact on factors of production (land, capital and labour of various skill categories) in terms of e.g. wages and (iv) CO2 emissions, land use, etc.

Spatial & Temporal extent

The output has the following spatial-temporal resolution and extent:

ParameterDescription
Spatial extent / country coverage
141 regions
Spatial resolutionWorld-regions (supranational)National
Temporal extentShort-term (from 1 to 5 years)Medium-term (5 to 15 years)Long-term (more than 15 years)
Baseline 2014
Temporal resolutionYears

Quality & Transparency

Quality

Model uncertainties

Models are by definition affected by uncertainties (in input data, input parameters, scenario definitions, etc.). Have the model uncertainties been quantified? Are uncertainties accounted for in your simulations?

not applicable
Not applicable for a CGE model.

    Sensitivity analysis

    Sensitivity analysis helps identifying the uncertain inputs mostly responsible for the uncertainty in the model responses. Has the model undergone sensitivity analysis?

    yes
    Both RunGTAP and RunDynam, the static and the dynamic version of the GTAP model, include a in-build tool to perform sensitivity analysis with respect to parameters.

      Have model results been published in peer-reviewed articles?

      yes
      GTAP model has been widely used in many publications. There is also a specific journal focused on GTAP modelling.

      Has the model formally undergone scientific review by a panel of international experts?

      Please note that this does not refer to the cases when model results were validated by stakeholders.

      no

        Model validation

        Has model validation been done? Have model predictions been confronted with observed data (ex-post)?

        yes
        The network of GTAP users represents an excellent resource for extension of the data base. Another benefit from broad participation is the extensive scrutiny to which the data base is subjected. Those who identify areas for improvement or extension of the data base are free to make this available to GTAP staff in order to have it considered for incorporation into the next release of the data base. The operational concept is "if you don't like it, help fix it!

          Transparency

          To what extent do input data come from publicly available sources?

          This may include sources accessible upon subscription and/or payment

          Entirely based on publicly available sources

          Is the full model database as such available to external users?

          Whether or not it implies a specific procedure or a fee

          yes
          Public Availability. The data base is made available to anyone requesting it, at a modest fee. This prevents needless duplication of effort in creating this public good. By charging for the data base we are also able to cover a portion of the costs incurred in constructing it. However, those who contribute in a significant way to the construction of this data base receive it for free, and are given access to pre-releases as well, alongside the GTAP Consortium members who provide the bulk of the financial support through their annual contributions to the Project.

            Have model results been presented in publicly available reports?

            Note this excludes IA reports.

            yes

            Have output datasets been made publicly available?

            Note this could also imply a specific procedure or a fee.

            no

              Is there any user friendly interface presenting model results that is accessible to the public?

              For instance: Dashboard, interactive interfaces...

              no

                Has the model been documented in a publicly available dedicated report or a manual?

                Note this excludes IA reports.

                yes
                One requirement for new contributions to the GTAP Data Base is that the sources and procedures used to create them be provided along with the data. This publication represents a summary of the documentation for the GTAP Data Base. Additional detail may be found on the GTAP website, or in the documentation of previous versions of GTAP. However, in spite of this extensive documentation, other questions about data sources and methods may arise. Therefore, we refer interested users to the chapter authors themselves in those cases where this document is insufficiently detailed. Often it is only through bilateral correspondence of this sort that data base limitations can be properly identified and remedied This takes us to the final ingredient of the GTAP Data Base, namely quality control.

                Is there a dedicated public website where information about the model is provided?

                yes

                Is the model code open-source?

                yes

                  Can the code be accessed upon request?

                  not applicable

                  The model’s policy relevance and intended role in the policy cycle

                  The model is designed to contribute to the following policy areas

                  • Trade

                  The model is designed to contribute to the following phases of the policy cycle

                  • Evaluation – such as ex-post evaluation
                  • Formulation – such as ex-ante Impact Assessments

                  The model’s potential

                  CGE models, like RunDynam, are computer-based simulations which calculate the future state of the global economy (including any country or region specifically analysed) as a consequence of a specified set of (trade) policy changes.

                  RunDynam is used, among other models and other approaches, for the economic analysis (Impact Assessment) within the different steps of any EU trade policy initiative. A Commission Impact assessment (IA) is needed before major trade negotiations can begin and for all other significant trade policy proposal, a trade sustainability impact assessment (SIA) is carried out during negotiations process and finally the economic assessment of the negotiated outcome (EANO) focuses on the economic value of trade barrier reductions following the final, precise outcome of the negotiations. In all these steps, RunDynam could be used for the economic assessment.

                  Reference for EC Impact assessment can be found here: https://ec.europa.eu/trade/policy/countries-and-regions/negotiations-and-agreements/.

                  Previous use of the model in ex-ante impact assessments of the European Commission

                  Use of the model in ex-ante impact assessments since July 2017.

                  2017
                  SWD/2017/0293 final

                  Impact assessment accompanying the document Recommendation for a Council Decision: authorising the opening of negotiations for a Free Trade Agreement with Australia

                  Lead by
                  TRADE
                  Run by
                  European Commission
                  Contribution role
                  baseline and assessment of policy options
                  Contribution details

                  The model helped to assess the following impacts:

                  • Adjustment, compliance or transaction costs
                  • EU Exports & imports
                  • Investment flows & trade in services
                  • Non-trade barriers
                  • Impacts on developing countries
                  • Goods traded with developing countries
                  • Economic growth and employment

                  2017
                  SWD/2017/0289 final

                  Impact assessment accompanying the document Recommendation for a Council Decision: authorising the opening of negotiations for a Free Trade Agreement with New Zealand

                  Lead by
                  TRADE
                  Run by
                  European Commission
                  Contribution role
                  baseline and assessment of policy options
                  Contribution details

                  The model helped to assess the following impacts:

                  • Adjustment, compliance or transaction costs
                  • EU Exports & imports
                  • Investment flows & trade in services
                  • Non-trade barriers
                  • Impacts on developing countries
                  • Goods traded with developing countries
                  • Economic growth and employment

                  Bibliographic references

                  Studies that uses the model or its results

                  No references in this category

                  Peer review for model validation

                  Shaping baseline scenarios of economic activity with CGE models: introduction to the special issue 

                  Published in 2020
                  Dellink, R., van der Mensbrugghe, D., & Saveyn, B. (2020). Shaping baseline scenarios of economic activity with CGE models: introduction to the special issue. Journal of Global Economic Analysis, 5(1), 1–27. https://doi.org/10.21642/jgea.050101af

                  Model documentation

                  No references in this category

                  Other related documents

                  Dynamic Modeling and Applications for Global Economic Analysis 

                  Published in 2009
                  Ianchovichina, E., & Walmsley, T. (Eds.). (2009). Dynamic Modeling and Applications for Global Economic Analysis. doi:10.1017/cbo9781139059923