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  • Engagement, advice and assurance

    In developing our estimates, we engage key stakeholders and subject matter experts within the ATO and the community. This includes tax gap experts, researchers, academics, government agencies and taxpayer representative groups.

    Our work with a broad range of advisors and stakeholders is ongoing. We are refining our methodologies and developing approaches to estimating other tax gaps.

    Holistic view of the tax gap program

    There are three main outcome principles to the tax gap program – our estimates need to be:

    • reliable
    • credible
    • meaningful.

    Each of these principles provide us with a framework, which we have codified in our reliability assessments for each estimate.

    Figure 2: Holistic view of the tax gap program

    Figure 2: Circular diagram. In the middle we have the holistic view of the tax gap program. On the outer rings we have: Credible - believable and complete, Reliable - dependable and trustworthy, and Meaningful - explained and communicated. In the middle ring we have what these measures are, as explained in the following content.


    For the 'reliable' principle, we assess ourselves against two outcomes – trustworthy and dependable.

    For an outcome to be trustworthy, the outcome needs to be transparent, concise and open to evaluation and critique. To achieve a dependable outcome, the estimate needs to use the best practice methods available. The results from those methods need to be repeatable, and the results must be evaluated by experts.


    For the 'credible' principle, we assess ourselves against two outcomes – believable and complete.

    For the credible principle, an outcome is believable when it explains why the gap is the size it is, and what the wider issues and impacts are. To be complete, the outcome needs to cover all the bases, including where applicable, associated issues and the black economy.


    For the 'meaningful' principle, we assess ourselves against two outcomes – explained and communicated.

    This principle ensures that outcomes obtained through our estimates are more than just numbers on a page. It means our stakeholders are able to understand the analysis. This helps them to engage with us in an informed conversation about the tax and superannuation systems. An outcome is explained if it answers the 'why' questions. It identifies the contributing factors of a gap, the key risks and drivers. It also acknowledges the caveats and limitations of our estimate.

    Lastly, all this information must be communicated. Effective communication means the analysis can be used by our stakeholders. It will inform strategy and treatment plans, and an understanding of the health of the system.

    The reliable and credible outcome principles of the tax gap program are externally assessed by our expert panel. They provide an independent assessment of our effectiveness at achieving these two principles.

    The 'meaningful' principle is assessed internally to ensure the 'reliable' and 'credible' outcomes are given appropriate context. This ensures the information is meaningful for the intended audience.

    Independent expert panel

    Recognising the importance of having reliable and credible tax gaps, we engage an independent expert panel. The panel provides advice on the suitability of our gap estimates and methodologies. We established the panel in 2013.

    The panel’s advice considers:

    • whether proposed methodologies can be relied on to produce a sufficiently robust gap estimate
    • whether the methodologies are likely to be broadly accepted as a way of estimating a gap, and whether alternative methodologies should be considered
    • international comparability, including global developments in the use of tax gap estimation methodologies and practices.

    The panel currently comprises:

    • Neil Warren – Emeritus Professor of Taxation, School of Taxation and Business Law, University of New South Wales. Neil is a respected economist, specialising in public sector economics with a special focus on taxation policy and fiscal federalism. Neil has received several grants, organised numerous conferences and consulted widely, preparing reports for state and federal government agencies. He has provided expert opinion to government inquiries and parliamentary committees, and advice to political parties, and welfare and industry groups. Neil has been a member of the panel since 2013.
    • Richard Highfield – a highly experienced tax professional having worked over 25 years in the Australian Taxation Office where he was a Second Commissioner of Taxation (1993–97), and in the fiscal areas of the International Monetary Fund (IMF) and the Organisation for Economic Co-operation and Development (OECD). Richard has a wealth of experience in both domestic and international taxation and is currently an adjunct professor with the School of Taxation and Business Law, University of New South Wales. He has been a member of the panel since 2013.
    • Saul Eslake – an independent economist, and vice-chancellor’s fellow at the University of Tasmania. Saul has decades of experience in the Australian financial markets, and has been previously employed as Chief Economist at ANZ, Bank of America Merrill Lynch, and National Mutual Funds Management. Saul joined the panel in 2017, following the stepping down of Chris Richardson.

    We look to the expert panel to review our detailed methodology. They provide independent assessment on the methodology and on the reliability rating for each of our tax gap estimates. Reliability ratings provide a transparent assessment of our gap estimates.

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      Last modified: 26 Nov 2019QC 53161