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Joint Research Center (JRC)
CORTAX

Corporate Tax Model

EconomyComputable General Equilibrium (CGE) ModelCorporate Tax

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
It would be unusual to include uncertainty in a deterministic model of this kind. (Extensive sensitivity analysis has been done, see next.)

    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
    For example, in the report for the Common Consolidated Corporate Tax Base (CCCTB) Impact Assessment, many dozens of sensitivity runs are reported (Álvarez-Martinez et al., 2016).

      Have model results been published in peer-reviewed articles?

      yes

        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)?

          not applicable
          As of yet, our simulations are for policies that have not yet been implemented.

            Transparency

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

            This may include sources accessible upon subscription and/or payment

            Based on both publicly available and restricted-access sources

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

            Whether or not it implies a specific procedure or a fee

            no
            All data sources are publicly available, though Orbis data (firm-level micro-data) is proprietary.

              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

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

                  no

                    Is the model code open-source?

                    no

                    Can the code be accessed upon request?

                    no