This chapter looks at the resources devoted to tax administrations and provides information on their workforce. It sets out how administrations are responding to new challenges and maintaining their capability while managing a workforce that has to adapt to a changing work environment.
Tax Administration 2024
Comparative Information on OECD and other Advanced and Emerging Economies
Tax Administration
Abstract
Central to a tax administration meeting its role in collecting revenue and providing services to citizens and businesses, is sufficient financial resources and a skilled workforce that can deliver quality outputs efficiently and effectively. This chapter examines the financial resources available to tax administrations, and how they are spent. It also provides information on tax administrations’ workforce, and how tax administrations are managing their people.
Operating expenditures
The overall level of resources devoted to tax administration is an important and topical issue for most governments, external stakeholders, and of course tax administrations themselves. While the budgetary approaches differ, in most jurisdictions the budget allocated is tied to the delivery of performance outputs which are outlined in an annual business plan.
When looking at the budget figures, around 80% of tax administrations report an increase in their operational expenditure between the years 2021 and 2022. This is slightly more administrations reporting an increasing budget than during the previous periods (see Table 10.1.).
Percentage of administrations
Note: The table is based on the data from 53 jurisdictions covered in this publication that were able to provide the information for the years 2018 to 2022.
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table A.16 Tax administration expenditures: Operating and salary expenditure, https://data.rafit.org/regular.aspx?key=74180905 (accessed on 10 September 2024).
However, this data should be treated with caution. While on paper a significant number of administrations saw increases in their budget, this may be a result of added responsibilities that come with additional budget as well as additional funding for investments in technology and new services to respond to taxpayer demands. It also does not take into account increases as a result of inflation, and that a significant part of the budget is needed for salary costs, accounting for on average 72% of operating budgets annually (see also Figure 10.1.). Any increases in budgets can be rapidly consumed by salary increases, which may be a contractual obligation.
Components of tax administration operating expenditure
As stated above, the largest reported component of tax administration operating budgets is staff costs, with salary alone accounting for on average 72% of operating budgets annually, even though there are some differences among jurisdictions (see Figure 10.1.).
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table D.6 Resource ratios: Cost, https://data.rafit.org/regular.aspx?key=74180898 (accessed on 10 September 2024)
Another important component is the operating cost for information and communication technology (ICT). Given the importance of ICT to tax administration’s operating models, they are constantly working on new approaches to ICT development such as the example provided by Australia (see Box 10.1).
The Australian Taxation Office (ATO) has established a Developer Services Branch and is working directly with its internal developer community through a working group to come up with new approaches in information technology (IT) development.
The working group is a small, selected group of developers who represent their areas across IT. This group aims to ensure ATO developers have a say on issues that will impact their work. To date this has seen the group advise on issues such as:
Process automation through the Automation Strategy
Test data management
Modernising standard operating environments
Developer tooling upgrades
Key outcomes from the group since its formation have been an increased satisfaction and awareness within the developer community of developer services, as well as a strong real time feedback channel with internal development users. This community is now providing peer assistance across business areas for common concerns or queries, strengthening the relationships between delivery groups and increasing the adoption of common guidance and patterns. This guidance is created by subject matter experts as well as end users.
Source: Australia (2024).
On average ICT expenditure accounts for about 11% of operating expenditure. However, reported levels of ICT expenditure vary enormously between administrations. For those administrations able to provide ICT-related cost, around 40% reported an annual operating ICT expenditure exceeding 10% of the administration’s total operating expenditure in 2022 and another 30% reported figures between 5% and 10% (see Table D.6).
While some of this variation can be explained by the different sourcing and business approaches, some cannot and point, at least on the surface, to expenditure levels that maybe somewhat below the support needed to provide the rapidly changing electronic and digital services administrations are increasingly being called upon to deliver. In parallel to this, administrations report that they are investing more in their cybersecurity practices, which are needed to protect the integrity of their system and maintain taxpayer trust. Box 10.5. of the 2023 edition of this series highlighted some examples (OECD, 2023[1]).
The averages for both items (salary and ICT) have remained stable over the past years as can be seen in Table 10.2.
Percentage of administrations
Note: The table is based on the data from jurisdictions covered in this publication that were able to provide the information for the years 2018 to 2022. The number of jurisdictions for which data was available is shown in parentheses.
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table D.6 Resource ratios: Cost, https://data.rafit.org/regular.aspx?key=74180898 (accessed on 10 September 2024).
Cost of collection
It has become a fairly common practice for tax administrations to compute and publish (for example, in their annual reports) a “cost of collection” ratio as a surrogate measure of their efficiency / effectiveness. The ratio is computed by comparing the annual expenditure of a tax administration, with the net revenue collected over the course of a fiscal year. Given the many similarities in the taxes administered by tax administrations, there has been a natural tendency by observers to make comparisons of “cost of collection” ratios across jurisdictions. Such comparisons have to be treated with a high degree of caution, for reasons explained in Box 10.2.
In practice there are a number of factors that may influence the cost/revenue relationship, but which have nothing to do with relative efficiency or effectiveness. Examples of such factors and variables include macroeconomic changes as well as differences in revenue types administered. These factors are further elaborated in Box 10.2.
Despite those factors, the “cost of collection” ratio is included in this report for two reasons:
1. The “cost of collection” ratio is useful for administrations to track as a domestic measure as it allows them to see the trend over time of their work to collect revenue and, as pointed out in Box 10.2., they may be able to account for the main factors that can influence the ratio; and
2. The inclusion of the “cost of collection” ratio and the accompanying comments set out in Box 10.2. can serve as a prominent reminder to stakeholders of the difficulties and challenges in using the easily calculated “cost of collection” ratio for international comparison.
Table 10.3. illustrates the change in the “cost of collection” ratios between 2018 and 2022 for the administrations included in this report. It shows that around three-quarters of the administrations had decreasing ratios between 2021 and 2022, which is very similar to the previous period. This is in contrast to the approximately 80% of administrations which had increasing ratios over the period 2019 to 2020, most likely a result of declining revenue collections during the COVID-19 pandemic.
Percentage of administrations
Note: The table is based on the data from 53 jurisdictions covered in this publication that were able to provide the information for the years 2018 to 2022.
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table D.6 Resource ratios: Cost, https://data.rafit.org/regular.aspx?key=74180898 (accessed on 10 September 2024).
Figure 10.2. looks at the movement in the “cost of collection” ratios over the five-year period from 2018 to 2022 from a jurisdiction-level perspective. However, as mentioned in Box 10.2., the chart and the underlying figures have to be interpreted with great care.
Note: When interpreting this chart the factors mentioned in Box 10.2. should be taken into account. Data for India, Israel and Türkiye have been excluded, see notes in Table A.16 Tax administration expenditures: Operating and salary expenditure.
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table D.6 Resource ratios: Cost, https://data.rafit.org/regular.aspx?key=74180898 (accessed on 10 September 2024).
Observed over time, a downward trend in the “cost of collection” ratio can appear to constitute evidence of a reduction in relative costs (i.e. improved efficiency) and/or improved tax compliance (i.e. improved effectiveness). However, experience has also shown that there are many factors that can influence the ratio which are not related to changes in a tax administrations’ efficiency and/or effectiveness and which render this statistic highly unreliable in the international context:
Changes in tax policy: Tax policy changes are an important factor in determining the cost/revenue relationship. In theory, a policy decision to increase the overall tax burden should, all other things being equal, improve the ratio by a corresponding amount, but this has nothing to do with improved operational efficiency or effectiveness.
Macroeconomic changes: Significant changes in rates of economic growth etc. or inflation over time are likely to impact on the overall revenue collected by the tax administration and the cost/revenue relationship.
Abnormal expenditure of the tax administration: From time to time, a tax administration may be required to undertake an abnormal level of investment (for example, the building of a new information technology infrastructure or the acquisition of more expensive new accommodation). Such investments are likely to increase overall operating costs over the medium term, and short of offsetting efficiencies which may take longer to realise, will impact on the cost/ revenue relationship.
Changes in the scope of revenues collected: From time to time, governments decide to shift responsibility for the collection of particular revenues from one agency to another which may impact the cost/revenue relationship.
From a fully domestic perspective, an administration may be able to account for those factors by making corresponding adjustments to its cost or collected revenue. This can make tracking the “cost of collection” ratio a helpful measure to see the trend over time of the administration’s work to collect revenue. If it were gathered by tax type, it may also help inform policy choices around how particular taxes may be administered and collected.
However, its usefulness with respect to international comparison is very limited. While administrations may be able to account for the above factors from a domestic perspective, it will be difficult to do this at an international level as such analysis would have to consider:
Differences in tax rates and structure: Rates of tax and the actual structure of taxes will all have a bearing on aggregate revenue and, to a lesser extent, cost considerations. For example, comparisons of the ratio involving high-tax jurisdictions and low-tax jurisdictions are hardly realistic given their widely varying tax burdens.
Differences in the range and nature of revenues administered: There are a number of differences that can arise here. In some jurisdictions, more than one major tax authority may operate at the national level, or taxes at the federal level may be predominantly of a direct tax nature, while indirect taxes may be administered largely by separate regional/state authorities. In other jurisdictions, one national authority will collect taxes for all levels of government, i.e. federal, regional and local governments. Similar issues arise in relation to the collection of social insurance contributions.
Differences in the range of functions undertaken: The range of functions undertaken by tax administrations can vary from jurisdiction to jurisdiction. For example, in some jurisdictions the tax administration is also responsible for carrying out activities not directly related to tax administration (for example, the administration of certain welfare benefits or national population registers), while in others some tax-related functions are not carried out by the tax administration (for example, the enforcement of debt collections). Further, differences in societal views may influence what an administration does, how it can operate and what services is has to offer. The latter may have a particularly significant impact on the cost/revenue relationship.
Finally, it should be pointed out that the “cost of collection” ratio ignores the revenue potential of a tax system, i.e. the difference between the amount of tax actually collected and the maximum potential revenue. This is particularly relevant in the context of international comparisons – administrations with similar cost/revenue ratios can be some distance apart in terms of their relative effectiveness.
In 2022, the administrations included in this report employed approximately 1.7 million staff (see Table A.18) making the effective and efficient management of the workforce critical to good tax administration. Having a competent, professional, productive and adaptable workforce is at the heart of most administrations’ human resource planning. With salary costs averaging more than 70% of operating expenditures, any significant budget change invariably impacts staff numbers.
The “double pressure” created from budgetary constraints and technology change, mentioned in the 2017 edition (OECD, 2017[2]) (see also Figure 10.3.), continues to be a significant management issue for most administrations. The challenge is compounded for some administrations which, due to contract restrictions or government mandates, may find it difficult to strategically down-size their operations other than through the non-replacement of staff who leave of their own accord.
Staff usage by function
Figure 10.4. provides average allocation of staff resources (expressed in full-time equivalents) across seven functional groupings used to categorise tax administration operations. It should be noted that for the ISORA 2023 survey, the functional groupings were revised splitting the category “All other functions” into four: (i) Dispute management; (ii) Human resource management; (iii) Information and communication technology support; and (iv) All other functions. This allows obtaining a better picture of staff usage by tax administrations.
Note: Excluding administrations that were unable to provide the break-down for all functions.
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Tables D.7 Staff allocation by location and function: Registration, services, processing, and audit and verification, D.8 Staff allocation by function: Debt collection, dispute management, and HR management, and D.9 Staff allocation by function: ICT support and all other functions, https://data.rafit.org/regular.aspx?key=74180899 (accessed on 10 September 2024).
While the detailed data for each administration in Tables D.7. to D.9. shows a significant spread of values and a number of outliers for each function, on average the “Audit, investigation and other verification” function and the “Registration, services, returns and payment processing” function are equally resource intensive, each employing on average 30% of staff. Both ratios, as well as the ratio for “Debt collection and related functions” have remained stable over recent years.
With advancements in technology, an ever-increasing availability of data, and constantly changing taxpayer expectations as regards service offerings, tax administrations are enhancing their information and communication technology as well as analytics capabilities. They employ increasing numbers of people with specialist skills or, where those positions do not exist in-house, contract them from outside.
ISORA 2023 looked at three of those skills and asked administrations to indicate whether they employ or contract people with behavioural science skills, user interface design skills, and/ or data science skills. Table 10.4. summarises the results and shows that:
Around half of the administrations use behavioural insights skills, either in-house, contracted as needed, or both in-house and contracted. How behavioural insights can help tax administrations is described in Chapter 6 and has also been explored in the 2021 OECD publication Behavioural Insights for Better Tax Administration: A Brief Guide (OECD, 2021[3])
User interface design is another specialist skill that has become more and more important. User interface design is the process of designing the interface between software solutions and humans, with the goal of ensuring that the software is easy to use. Its importance can be seen by more than 70% of administrations employing and/ or contracting people with this skill.
Data scientists are employed and/or contracted by close to 80% of administrations. With the increasing amounts of data available to and manged by tax administrations this is not surprising.
Percentage of administrations
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table B.15 Specialist skills, https://data.rafit.org/regular.aspx?key=74180914 (accessed on 10 September 2024).
Staff metrics
The ISORA survey also gathers key data concerning the age profiles, length of service, gender distribution and educational qualifications of tax administration staff: see Tables D.10. to D.16. and A.22. to A.33. While interpreting this data it should be noted that combined tax and customs administrations were allowed to use their total workforce for answering the underlying survey questions as it may be difficult for them to separate the characteristics of the tax and customs workforce.
Age profiles
While there are significant variations between the age profiles of tax administration staff (see Tables D.12. and D.13.), it is interesting to see that there are also differences when viewed across different regional groupings. This may be the result of a complex mix of cultural, economic, and sociological factors (for example, economic maturity, recruitment, remuneration, and retirement policies).
Figure 10.5. illustrates that staff are generally younger in administrations in the regional groupings of “Asia-Pacific” and “Middle East and Africa” where, on average, around 30% of staff are below 35 years of age, whereas in the “Americas” and “Europe” this percentage drops to below 20%. At the same time, administrations in the “Americas” and “Europe” have a large percentage of staff older than 54 years.
Percentage of staff by age bands for selected regional groupings
Note: The following administrations are included in the regional groupings: Americas (9) – Argentina, Brazil, Canada, Chile, Colombia, Costa Rica, Mexico, Peru and the United States; Asia-Pacific (11) – Australia, China (People’s Republic of), Hong Kong (China), India, Indonesia, Japan, Korea, Malaysia, New Zealand, Singapore and Thailand; Europe (31) – Austria, Belgium, Bulgaria, Croatia, Cyprus, Czechia, Denmark, Estonia, Finland, France, Georgia, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, the Slovak Republic, Slovenia, Spain, Sweden, Switzerland and the United Kingdom; Middle East and Africa (6): Israel, Kenya, Morocco, Saudi Arabia, South Africa and Türkiye.
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Tables D.12 Staff age distribution: Staff below 45 years and D.13 Staff age distribution: Staff 45 years and above, https://data.rafit.org/regular.aspx?key=74180899 (accessed on 10 September 2024).
Looking at the jurisdiction specific data, the percentage of staff older than 54 years grew in two-thirds of administrations over the five-year period from 2018 to 2022 (see Figure 10.6).
Note: Only includes jurisdictions for which data was available for both years. Data for Iceland and Saudi Arabia has been excluded due to the mergers of the tax administration with the customs administration.
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table D.13 Staff age distribution: Staff 45 years and above, https://data.rafit.org/regular.aspx?key=74180899 (accessed on 10 September 2024).
Source: OECD Secretariat calculations based on CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Tables D.12 Staff age distribution: Staff below 45 years, D.13 Staff age distribution: Staff 45 years and above, D.14 Length of service: Less than 10 years, and D.15 Length of service: 10 years or more, https://data.rafit.org/regular.aspx?key=74180899 (accessed on 10 September 2024).
Length of service
The difference in age profiles is also largely reflected in the length of service of tax administration staff. Figure 10.7. indicates that a significant number of administrations will not only face a large number of staff retiring over the next years, but that many of these staff will be very experienced, thus raising issues about retention of key knowledge and experience.
Gender distribution
In light of the strong public interest in gender equality, administrations were invited to report total staff and executive staff respectively by gender. As can be seen in Figure 10.8., while many administrations are close to the proportional line, typically female staff remains proportionally underrepresented in executive positions and significantly underrepresented in a number of administrations, something that has remained unchanged since the 2017 edition of this report (OECD, 2017[2]).
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table D.16 Gender distribution, https://data.rafit.org/regular.aspx?key=74180899 (accessed on 10 September 2024).
Looking at the overall averages, whilst there are variations between jurisdictions (see Table D.16.), on average the share of female employees of total staff and executive staff has remained largely unchanged over the five-year period from 2018 to 2022, with a small increase of around 7% of female executives (see Table 10.5.). The jurisdiction-level data shows that in about two-thirds of administrations the percentage of female executives has increased since 2018 (see Table D.16.).
Note: The table shows the share of female employees of total staff and executive staff for the jurisdictions covered in this publication that were able to provide the information for the years 2018 to 2022. The number of jurisdictions for which data was available is shown in parentheses.
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table D.16 Gender distribution, https://data.rafit.org/regular.aspx?key=74180899 (accessed on 10 September 2024).
The ISORA survey also asked administrations to indicate whether staff has self-identified as neither female nor male (referred to as “other” gender for the purposes of the survey). Seven administrations report capturing information on “other” gender and two administrations, Australia and New Zealand, reported having staff who self-identified as “other,” in the case of Australia also at executive level (see Tables A.24. and A.27.).
To understand how the gender distribution might develop in the future, the ISORA 2023 survey asked tax administrations for the first time to report the percentage of recruits who are female. As can be seen in Figure 10.9., in the vast majority of administrations covered in this publication, females make up more than half of all staff that joined the administration during the fiscal year.
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table D.16 Gender distribution, https://data.rafit.org/regular.aspx?key=74180899 (accessed on 10 September 2024).
Staff attrition
Staff attrition, also called staff turnover, refers to the rate at which employees leave an organisation during a defined period (normally a year). High attrition rates may result from a variety of factors, such as downsizing policies, demographics or changing staff preferences. The attrition rate should be considered together with other measures, such as the hire rate, which looks at the number of staff recruited during a defined period, when evaluating the human resource trends of an administration.
While a high attrition rate combined with a low hire rate is usually associated with a general downsizing policy, administrations should perhaps be concerned where both rates are high. Recruitment is costly, not only the recruitment process itself but also the cost and time for training and supporting new staff members.
Having attrition rates that are too low may also not be ideal. While an organisation is growing, a low attrition rate may be desirable. However, in situations where both the attrition rate and the hire rate are low, an organisation may not have the ability to recruit new skills as all positions are filled. This could be an issue particularly for administrations that are undergoing transformation and are therefore in need of staff with skills that are different from what is currently available within the administration.
While what is considered a “healthy” attrition rate differs between industry sectors or jurisdictions, the average attrition and hire rates for administrations participating in this publication of around 7% in 2022 would seem to present a reasonable range for tax administrations of between 5% and 10%. It is worth noting that the average attrition and hire rates for 2022 are now back to pre-pandemic levels, even slightly above. (See Table 10.6.)
Note: The table shows the average attrition and hire rates for the jurisdictions covered in this publication that were able to provide the information for the years 2018 to 2022. The number of jurisdictions for which data was available is shown in parenthesis. Data for China (People’s Republic of), Iceland, Norway and Saudi Arabia was excluded from the calculation as the result of extraordinary staff transfers over the period 2018 to 2021 which were recorded as recruitments, thus distorting their averages for those years (see notes in Table A.23).
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table D.10 Staff dynamics, https://data.rafit.org/regular.aspx?key=74180899 (accessed on 10 September 2024).
However, when looking at specific administration data, it becomes apparent that “attrition and hire” rates cover a very broad range. Figure 10.10. shows the relationship between tax administration attrition and hire rates. It illustrates that there are a number of administrations with attrition and hire rates well above 10% (upper-right box), while others show very low attrition and hire rates (lower-left box).
Note: Attrition rate = number of staff departures/average staffing level. Hire rate = number of staff recruitments/ average staffing level. The average staffing level equals opening staff numbers + end-of-year staff numbers/2.
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table D.10 Staff dynamics, https://data.rafit.org/regular.aspx?key=74180899 (accessed on 10 September 2024).
People management
Effective people management in tax administration involves comprehensive recruitment, training, and retention strategies. By investing in continuous professional development, tax administrations can keep their staff informed of the latest laws, technologies, and working practices and methods. Moreover, a focus on employee well-being and engagement can lead to higher job satisfaction, lower attrition rates, and a more dedicated workforce. This can help in cultivating a positive organisational culture that values integrity, accountability, and excellence, which are crucial for a well-functioning tax system. Administrations invest in this and around 3% of staff are engaged with human resource (HR) management (see Figure 10.4.).
To better understand tax administrations approaches towards people management, the ISORA 2023 survey gathered a significant amount of data points which are summarised below in four categories: (i) talent recruitment and retention, (ii) learning and development, (iii) staff motivation and performance, and (iv) diversity management.
Talent recruitment and retention
Recruiting and keeping talent are important factors for the long-term success of a tax administration. This includes identifying the needs for future talent and having a strategic approach towards managing the workforce. This section is looking at four areas that contribute to having a successful talent recruitment and retention approach:
The availability of an HR strategy or multi-year workforce plan,
The existence of a staffing plan,
The assessment of capability needs within the administration, and
The administration’s autonomy in human resource management.
Human resource strategy / workforce plan
An HR strategy, or a multi-year workforce plan, which is designed to support the overall objectives of the tax administration by (a) identifying and defining the skills needed to meet those objectives and (b) then systematically recruiting, developing, and retaining skilled people, plays an essential part in an effective and sustainable tax administration.
As shown in Table 10.7., the large majority of administrations, around 90%, reported the existence of an HR strategy that sets out their key plans and objectives in management of its people. There might be considerable benefit for those that have not already established this practice to do so.
Percentage of administrations
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Tables B.10 HR management approach: Strategy / multi-year work force plan and training strategy, and B.11 HR management approach: Support for new staff and staffing plan, https://data.rafit.org/regular.aspx?key=74180914 (accessed on 10 September 2024).
For those that have an HR strategy, around 80% indicated that they take a competency-based approached, where the competencies and performance criteria are described for each position, and around three-quarters of administrations reported that they have a job competency dictionary. In addition, close to 85% reported having a job catalogue in place, while 90% of administrations indicated that there are job descriptions for the various positions. (See Table 10.7.)
Staffing plan
A workforce plan or strategy is essential to define the longer-term approach for recruiting, developing and retaining people and to ensure that the right skills are available at the right time. Contrary to this, a staffing plan will focus on the short-term needs of the administration and will help understand the immediate personnel requirements, including the number and types of staff required.
As can be seen in Table 10.7., around 80% of administrations reported having a staffing plan, and almost all of those have also put in place a recruitment plan.
Assessment of capability needs
The changes tax administrations are managing at present, whether technological, international, policy or budget driven, are significant. Tax administrations will have to adapt to the culture and services expected by taxpayers, particularly the next generation of taxpayers. To assist in the HR short-term and long-term planning process, around three-quarters of tax administrations covered in this publication reported assessing the current and future capability needs (see Table 10.8.).
Utilizing the power of data, close to 90% of administrations that assess capability needs reported the use of data analysis as part of the evaluation process and all of them review the evaluation on a regular basis. Illustrating the strong linkages between the capability needs assessment and workforce planning, 86% reported that the evaluation outcomes are reflected in the HR strategy. Moreover, around 80% indicted having a formal plan to address gaps in staff capability (see Table 10.8.).
Percentage of administrations
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table B.14 Capability needs assessment, https://data.rafit.org/regular.aspx?key=74180914 (accessed on 10 September 2024).
China (People’s Republic of) – Intelligent management of employee information
To aid in the selection and recruitment of employees across different departments and roles, the State Tax Administration (STA) has conducted in depth comparative analysis of employee data to build an accurate profile of each employee:
Integrated analysis through collecting employee data from numerous sources: By collecting tax officials’ data recorded in government affairs, business systems and other relevant systems a "live profile" is built for each tax official which can be analysed and compared with the profiles of other officials.
Real-time employment updates: The recruitment of new employees and change in role or promotion of current employees is updated on the online management system, allowing for the real-time monitoring and analysis of personnel. This allows for planning and helps to ensure all areas are adequately resourced.
Intelligent Management Network: Through building an “intelligent management network” that connects the five levels of the national tax system, the structure of all the different teams of officials is presented in a panoramic manner. This allows for the comparison and analysis of human resource allocation and personnel performance across the whole tax administration, aiding in any decision-making on resource management.
France – Recruitment Campaign
The Directorate General of Public Finances (DGFiP) has launched a major digital communications campaign aimed at making its jobs more attractive to prospective employees. The campaign includes the creation of a new website dedicated to recruitment highlighting the wealth of jobs and career paths within DGFiP, and the roll-out of a new advertising campaign.
By clearly communicating its values and culture through online channels (social networks and its website), DGFiP is attracting the interest of a wider range of potential candidates. To do this, it shares inspiring stories of its managers, social and environmental initiatives, and significant events, in order to show the human side of DGFiP. The campaign uses video testimonials to capture attention and showcase to candidates the diversity of jobs available, career opportunities and the various benefits.
Employees and managers of DGFiP are actively involved in the strategy by promoting DGFiP and their day-to-day work in various ways. For example, the local directorates consolidate the image of public finances by taking part in major local student fairs and relaying campaigns to partner administrations.
Sources: China (People’s Republic of) (2024) and France (2024).
Autonomy in human resource management
As set-out in Chapter 9 on governance arrangements, tax administrations can benefit from a high degree of autonomy in relation to recruitment, development and remuneration to ensure the effective and efficient operation of the tax system. As can be seen in Table 10.9., the vast majority of administrations report having autonomy in HR related matters. However, a look at the data by jurisdiction does show that a small number of administrations only have autonomy in some areas. Moreover, even where tax administrations have autonomy, there are often regulatory or budgetary constraints that may inhibit the effective use of these powers.
While the degree of autonomy remains largely consistent across the different areas, there is one notable exception, namely the “Placement of staff within a salary range” which, with 64%, is significantly below the ratings of other HR powers administrations typically have. This may be a particular concern in the areas of information and communication technologies, data science, cyber security, and other positions where tax administrations compete with private sector entities for skilled people.
Percentage of administrations
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table B.7 Human resource authority, https://data.rafit.org/regular.aspx?key=74180914 (accessed on 10 September 2024).
Learning and development
The changes that digitalisation and the digital transformation of tax administrations bring to the operating models of tax administrations means that not only will new staff need to be hired, but the skills of existing staff may need to be developed. A key issue in this respect is how to transition and support staff through this change. At the same time, administrations need to remain conscious of the large number of staff retiring over the next few years (see in the sub-section on “Staff metrics”) and how to transfer their knowledge and experience to new employees.
Training strategy
As shown in Table 10.10., tax administrations have recognised the importance of preparing existing staff for this transition and more than 90% have developed training strategies that allow existing staff to upgrade their skills. The need to increase capability internally is particularly important where employment conditions, contractual requirements, and remuneration levels, make it difficult to hire skilled staff, particularly, when competing with the private sector for skills.
Of those administrations that have training strategies, almost 90% have put in place a formal training cycle process, and more than 95% have a specific training plan which is important when investing in new capabilities to support the ability to implement change more rapidly and to support the development and adoption of new services and products, particularly involving digital technology.
Türkiye has provided training to colleagues working in behavioural approach teams through in-person workshops. Behavioural approaches are getting increased attention by tax administrations as an area of interest to improve compliance levels. This training aims to provide a forum where views can be exchanged on the best way to deliver a consistent high quality customer service.
The first workshop was held in December 2023 in Ankara and brought together 141 people from the central and provincial behavioural approach units, to develop evidence based and taxpayer focused policies. Taxpayer decisions and the factors affecting these decisions were examined, to work out how to achieve higher levels of voluntary tax compliance. Staff were also briefed on other behavioural public policy units established in different jurisdictions. This was concluded with communication and diction training, to aid officials in communicating effectively with taxpayers.
Source: Türkiye (2024).
Percentage of administrations
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table B.10 HR management approach: Strategy / multi-year work force plan and training strategy, https://data.rafit.org/regular.aspx?key=74180914 (accessed on 10 September 2024).
Supporting new staff
Supporting new staff when they join the administration is important for ensuring a smooth integration, so that they are quickly operational and can perform at the highest level. Induction programmes and mentoring initiatives provide newcomers with the essential knowledge, skills, and cultural understanding needed to navigate their new environment effectively. It can also have a positive impact on the long-term motivation of new staff.
As illustrated in Table 10.11., more than 90% of tax administrations covered in this publication have programmes in place to support new staff, with almost all of those running formal induction programmes. At the same time, only around two-thirds of the administrations have introduced formal mentoring programmes for new staff. This could be a missed opportunity, particularly in a remote working environment where new staff might not directly feel part of the wider organisation. Here, remote mentoring programmes might contribute to lower attrition rates, quicker skill development, and an increased engagement.
Leadership development and succession planning
Leadership development and succession planning are important for continuity and stability within tax administration. It ensures there are always viable candidates within the administration who can quickly take over when required, increasing the resilience of the tax administration. It also aids in the vital transfer of knowledge between successors, and provides leadership certainty to staff.
Around three-quarters of administrations have leadership and talent management programmes. As regards knowledge transfer, around 75% have a personalised knowledge transfer approach, i.e. where knowledge is transferred from one tax official to another on a one-to-one basis, and around 90% operate a system where knowledge transfer is documented, i.e. the knowledge is converted into products, such as documents or videos, that can be consumed by many. (See Table 10.11.)
Percentage of administrations
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Tables B.10 HR management approach: Strategy / multi-year work force plan and training strategy, and B.11 HR management approach: Support for new staff and staffing plan, https://data.rafit.org/regular.aspx?key=74180914 (accessed on 10 September 2024).
Virtual training
During the COVID‑19 pandemic, many tax administrations reported transitioning their training programmes from face-to-face contact to a virtual environment. Tax administrations report that these practices brought significant benefits to the administration and participants, and as a result they continue being adapted for the longer term. Previous editions of this report showcased examples of this, such as the use of live online training sessions or pre-recorded videos/webinars (OECD, 2021[4]) or interactive applications that can also be used as part of recruitment efforts (OECD, 2023[1]).
While moving to a virtual training environment may have some up-front costs, it may save costs in the longer term as once produced, pre-recorded training material can be viewed at any time, from anywhere. Remote training can reduce travel expenses and can allow staff to learn at their own pace and convenience as well as increasing the number of staff members that can follow a course. New technologies are also helping facilitate the collaborative learning aspects, increasing the quality of the training experience.
In addition to the virtual training programmes produced by tax administrations themselves, international organisations are also producing e-learning courses specifically designed for tax administrations. One of these programmes is the Virtual Training to Advance Revenue Administration (VITARA) initiative, a joint project of four organisations, which is described in more detail in Box 10.5.
VITARA is an online course specifically designed for tax administrations. The course consists of several short, structured online modules. It is a joint project of four organisations, the Inter-American Center of Tax Administrations (CIAT), the International Monetary Fund (IMF), the Intra-European Organisation of Tax Administrations (IOTA) and the OECD.
The VITARA course content is tailored to senior managers and executives of tax administrations of developing countries. Yet other tax officials, including from advanced economies, could also benefit from following the different course modules. All modules are free of charge and there are no prerequisites or qualification requirements.
The VITARA curriculum represents a comprehensive training package for tax administration management. It consists of two parts and includes the following topics:
Part A. Institutional governance, management, and support
Institutional governance
Compliance risk management
Organization
Strategic management
Information technology and data management
Reform management (Fundamentals and Specific Topics)
Human resource management
Performance management
Enterprise risk management
Part B. Core functions of tax administration
Introduction to tax administration
Taxpayer registration
Taxpayer services
Filing of declarations
Payment and debt collection
Audit program
Dispute resolution
Revenue management
By September 2024, ten VITARA modules have been developed in English, and some are also available in Spanish, French and Arabic. New English modules as well as further translations will follow. The available modules (underlined above) can be accessed here: https://www.imf.org/en/Capacity-Development/Training/ICDTC/Search?sortby=Relevancy&sortdir=Descending&keywords=VITARA (accessed on 10 September 2024).
To support learners, and to provide easy and free access to the content of the VITARA online modules (particularly to those that have no stable internet access), the VITARA partners have started reproducing the module content in so called “Reference guides”. By September 2024, five Reference guides have been published:
Human Resource Management (CIAT, IMF, IOTA, OECD, 2024[5])
Organisation (CIAT, IMF, IOTA, OECD, 2024[6])
Strategic management (CIAT, IMF, IOTA, OECD, 2023[7])
Reform Management Fundamentals: Setting Up a Reform Program (CIAT, IMF, IOTA, OECD, 2024[8])
Reform Management Specific Topics: Managing a Reform Program (CIAT, IMF, IOTA, OECD, 2024[9])
Staff motivation and performance
Maintaining the motivation of employees is crucial to running a successful organisation, driving productivity and engagement which in turn helps the administration to achieve its objectives. Having a performance management system in place can complement this, through establishing clear goals, expectations, and providing a mechanism for regular feedback and development opportunities.
Staff surveys
Conducting regular surveys to gather employee perceptions of the workplace and HR management to better inform decision making in these areas can be of particular importance in times of change. Measuring staff engagement, satisfaction and motivation, sharing the results of surveys of these areas with staff, and involving them in the selection, design and implementation of changes has proven a successful formula to increase productivity in a number of tax administrations.
Around 70% of administrations survey their staff periodically on attitudes, perceptions and workplace satisfaction, although the frequency of surveys may vary. More than 90% of those administrations assess staff engagement, share the results with staff, and involve their staff when considering responses to survey findings. (See Table 10.12.)
Percentage of administrations
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table B.9 HR management approach: Staff surveys, https://data.rafit.org/regular.aspx?key=74180914 (accessed on 10 September 2024).
Performance management systems
Almost all tax administrations report that they have performance management systems in place. Most of these conduct the evaluation on an annual basis (or even more often) and include specific objectives for each staff member in this process. The importance of individual development plans has also been recognised and only 15% of the administrations do not include them in their performance management system. (See Table 10.13.)
Percentage of administrations
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table B.8 Remuneration and performance management, https://data.rafit.org/regular.aspx?key=74180914 (accessed on 10 September 2024).
Remuneration and staff performance
Linking performance to pay or some other types of rewards may be a powerful motivator and increase staff engagement. The nature of the reward mechanisms varies greatly and can include individual or collective salary increases, flexibility to adjust salary scales, promotions, individual or collective bonuses, and non-monetary rewards. At the same time, it may have adverse effects on the workplace and culture by creating a competitive environment.
A significant number of administrations, three-quarters, can link performance to pay and reward. While good performance can typically result in increased remuneration (93%), there are a number of administrations where poor performance can result in reduced salary (36%) or the denial of annual increments (50%).
Percentage of administrations
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table B.8 Remuneration and performance management, https://data.rafit.org/regular.aspx?key=74180914 (accessed on 10 September 2024).
Supporting staff
The changes tax administrations are managing, whether technology, policy or budget driven, are constant. In addition, the wider digital transformation of the economy is changing the service expectations of taxpayers. To maintain staff motivation and performance, tax administrations are considering the best way to support staff through these changes, as well as ensuring they have the right tools for the tasks.
Technology is playing a key role in this. This includes the use of artificial intelligence, machine learning and robotic process automation (RPA) to automate some of the core tasks within a tax administration. Table 6.10. in Chapter 6 highlights the rapid growth in the use of such services with, for example, almost two-thirds of administrations reporting that they now using or planning to use RPA. This is helping tax administrations respond to budgetary and workforce pressures as it is freeing up resource for staff to be focussed on more complex tasks.
Box 10.6. illustrates the wide range of uses that automation is being put to. Further examples are included in Box 9.5. of the 2023 edition of this series (OECD, 2023[1]).
France – Using generative artificial intelligence to assist with processing parliamentary amendments to the budget bill
The LLaMandement Project, developed by DGFiP, represents a significant leap forward in the legislative process, particularly in the handling of the Finance Bill which is the cornerstone of France's annual budget.
The Project uses Artificial Intelligence (AI) to streamline the processing of parliamentary amendments by DGFiP, automating the summary and allocation of these amendments to the correct teams. This innovation is instrumental in shaping the nation's budget by ensuring that financial legislation is handled with the utmost efficiency and accuracy.
This initiative directly impacts the legislative process by enhancing the capacity of parliamentary and administrative staff to manage and scrutinise the vast number of amendments presented during the Finance Bill discussions. With LLaMandement, the process of reviewing over 10 000 amendments becomes significantly more manageable, allowing for a more focused and informed debate on the nuances of financial legislation. This in turn facilitates a more thorough consideration of the budgetary implications of each amendment, ensuring that the final Finance Bill is both comprehensive and reflective of the legislative intent.
DGFiP has released the tool’s source code, training data, and usage documentation to the public domain. This open-source philosophy enhances the project's transparency, inviting collaboration, external evaluation, and further development from a wider community. It fosters an environment that enables citizens, academic institutions, and industrial partners to contribute to and benefit from the state’s advancements in generative AI.
For more information, please see here: https://arxiv.org/pdf/2401.16182.pdf (accessed on 10 September 2024).
Lithuania – Robotic Process Automation
In striving to achieve operational excellence, Lithuania’s State Tax Inspectorate (STI) recently completed the automation of its processes by investing in Robotic Process Automation (RPA) software and the requisite licenses.
Two pivotal areas targeted for automation were the revision of unpaid taxes and the compilation of administrative protocols. By automating the process of compiling the protocols of administrative misconduct, the STI can now swiftly implement fines for non-submitted tax returns to a larger number of taxpayers. This measure not only encourages timely tax return submissions, but also contributes additional funds to the state budget. Furthermore, automating the process of reviewing unpaid taxes and fines for administrative misconduct streamlines the administration of fines. It enables the STI to respond promptly to changes in a person's assets, and collection imposed fines in instalments.
By the end of 2023, 22 200 decisions were automated. This translated to a saving of 581 working days, underscoring the efficiency gains brought about by automation. Similarly, the automation of administrative offense protocols proved fruitful for STI. Originally targeting 18 000 protocols in 2023, the organization surpassed expectations by drafting 31 285 protocols by year-end which translated to a saving of 9 995 working days.
Looking ahead, STI is dedicated to enhancing its operations by empowering its specialists to automate new processes.
Saudi Arabia – Using Robotic Process Automation for operational tasks
ZATCA in Saudi Arabia has implemented RPA to significantly improve its operational efficiency and accuracy. By automating repetitive and rule-based tasks, RPA has relieved the burden on ZATCA's workforce and accelerated tax and customs processes. This automation has resulted in faster response times and reduced errors associated with manual data entry, leading to greater overall accuracy in financial transactions, reporting, and customs operations.
The integration of RPA has brought several key benefits to ZATCA across various areas. Duties such as data entry, document verification, and compliance inspections have been automated, improving efficiency and minimizing potential human errors. Similarly, RPA has streamlined HR operations, optimizing employee management and administrative tasks. Customer service has also been enhanced through the automation of routine ticketing processes, resulting in quicker resolutions and improved customer satisfaction.
ZATCA has further leveraged RPA in infrastructure system monitoring, enabling continuous and automated monitoring for proactive issue detection and ensuring system reliability. Additionally, data gathering and report generation have been automated, ensuring high accuracy in reporting and facilitating faster decision-making processes.
Overall, ZATCA's adoption of RPA demonstrates its commitment to innovative solutions in managing tax and customs procedures. By automating key areas such as Customs, HR operations, Ticket Handling, Infrastructure System Monitoring, and Reporting, ZATCA has not only streamlined processes but also improved customer service and decision-making capabilities. This strategic implementation of RPA has propelled ZATCA towards greater operational efficiency and accuracy.
Sources: France (2024), Lithuania (2024) and Saudi Arabia (2024).
Diversity management
Having a diverse workforce that represents the population helps the administration to better serve its customers and encourages an inclusive working environment. Introducing a comprehensive diversity policy can be a good way to promote this, by integrating diversity and inclusion into formal processes within the administration and promoting a culture where different perspectives are valued and encouraged, improving staff morale. As can be seen in Table 10.15., tax administrations have embraced this approach with 85% having a formal diversity policy.
Having a workforce with a wide range of viewpoints and experiences can also improve decision making and aid the tax administration in its service delivery, through enhancing trust with taxpayers. Conducting periodic staff surveys on diversity and inclusion can be a helpful tool in both assessing the effectiveness of current diversity policies and identifying possible areas for improvement and new focus areas. They can guide leadership teams in developing new initiatives to target any inequalities or challenges identified by the survey. To understand how staff perceive the administration’s approach towards diversity, around half of the administrations reporting conducting staff surveys on diversity and inclusion on a periodic basis (see Table 10.15.) Additionally, there may be other tools that administrations identify to maintain an inclusive and diverse workforce, such as staff networks and education campaigns.
Percentage of administrations
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Tables B.9 HR management approach: Staff surveys, B.12 HR management approach: staffing plan and flexible working arrangements, B.13 HR management approach: Leadership development, time reporting, diversity policy, https://data.rafit.org/regular.aspx?key=74180914 (accessed on 10 September 2024).
The Finnish Tax Administration promotes equality and non-discrimination in all its operations, both as an employer and providing taxpayer services.
Several measures are in place to ensure fair treatment and opportunities for all employees. A code of conduct has been established for both personnel and supervisors, emphasising the prevention of harassment, discrimination, and other inappropriate behaviours. Diversity initiatives are integrated into the employee experience and early care models. Anonymous job searches have been piloted, ensuring recruiters initially have no access to personal data to avoid bias. Remote work options have expanded, enabling hiring from various locations across Finland. Job titles have been changed into gender-neutral forms, and access to information in the second official language, Swedish, has been improved. There is also a dedicated working group on equality focused on promoting diversity and inclusion in everyday work.
In terms of equality towards taxpayers, the focus is on being inclusive and accessible. Diverse service channels are provided to accommodate different needs, with services designed to be accessible and user-friendly. Timely and accessible customer communication is prioritised and staff are trained in equality principles and practices. Monitoring and collecting customer feedback ensures the quality and accuracy of services.
Furthermore, there is ongoing dialogue with taxpayers and stakeholders, including minority organisations, to help identify development needs and set priorities. For the years 2023-2025, the main priorities are cognitive and linguistic accessibility, staff skills and culture.
Source: Finland (2024).
Flexible working arrangements
One way to support diversity in tax administrations is to facilitate flexible working arrangements, such as flexible working hours or remote working opportunities. These arrangements are increasingly important in today’s work environment as they enable employees to balance their professional and personal lives more effectively, leading to a higher job satisfaction and productivity. By accommodating diverse work preferences and needs, administrations can attract and retain top talent, reduce absenteeism, and foster a more engaged and motivated workforce.
Policies for flexible working arrangements exist in around 90% of the administrations covered by this publication. In almost all of those administrations staff can work flexible working hours and the vast majority offer staff the possibility to work from home or elsewhere on an occasional and regular basis. (See Table 10.15.)
Figure 10.11. illustrates the percentage of:
Staff that is able to work remotely, i.e. staff have the IT infrastructure to enable them to perform remotely all the tasks they would perform in the office, and
Staff that works remotely at least 20% of the year, i.e. one or more days per week, on average.
Percentage of staff able to work remotely and those working remotely at least 20 percent of the year
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table B.12 HR management approach: staffing plan and flexible working arrangements, https://data.rafit.org/regular.aspx?key=74180914 (accessed on 10 September 2024)
Further, Table 10.15. shows that around 40% of administrations have also introduced the possibility for executives to work part-time, and as can be seen in Figure 10.12. executives make use of those arrangements.
Source: CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table B.12 HR management approach: staffing plan and flexible working arrangements, https://data.rafit.org/regular.aspx?key=74180914 (accessed on 10 September 2024)
As tax administrations reflect on the working practices established as part of the pandemic response, the impact of longer-term hybrid or remote working is also being considered. This was explored in more detail in the OECD report Tax Administration: Towards sustainable remote working in a post COVID-19 environment (OECD, 2021[10]).
People management: A high-level picture
Using different aspects and data points from the 2023 ISORA survey, the people management section examines tax administrations’ approaches towards (i) talent recruitment and retention, (ii) learning and development, (iii) staff motivation and performance, and (iv) diversity management. Whilst the various aspects of people management that were explored in ISORA 2023 should not be considered exhaustive and do not have equal weight or significance, their occurrence or lack thereof can provide some indication of the capability of tax administrations in that area.
Figure 10.13. aims to provide a high-level picture of people management in tax administration. It does not name individual tax administrations but rather combines a set of data points providing an overall view for each of the four different categories. The scoring and weighing of the data points takes account of the different nature and level of detail of the underlying ISORA questions.
For each of the four categories, the figure shows the range of administrations that are between the lower and upper quartile (illustrated by the “boxes”), with the median represented by the horizontal lines drawn through the boxes. The lines extending the boxes vertically (the “whiskers”) indicate the range of administrations that are in the upper and lower quartiles.
The figure indicates that tax administrations have relatively advanced approaches regarding talent recruitment and retention, learning and development, and staff motivation and performance. The median score for tax administrations as regards those categories is at 80% or above, which indicates that based on ISORA data the majority of administrations have built their capabilities in those areas.
The picture is slightly different as regards diversity management where the median score for tax administrations is below 70%. While still positive, in contrast to the other categories this an area with scope for additional gains.
Source: OECD Secretariat calculations based on CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, https://data.rafit.org/regular.aspx?key=74180914 (accessed on 10 September 2024)
References
[8] CIAT, IMF, IOTA, OECD (2024), Reform Management Fundamentals: Setting Up a Reform Program, OECD Publishing, Paris, https://doi.org/10.1787/4d33b619-en.
[9] CIAT, IMF, IOTA, OECD (2024), Reform Management Specific Topics: Managing a Reform Program, OECD Publishing, Paris, https://doi.org/10.1787/1fc51bcf-en.
[5] CIAT, IMF, IOTA, OECD (2024), VITARA Reference Guide: Human Resource Management, OECD Publishing, Paris, https://doi.org/10.1787/6ef70142-en.
[6] CIAT, IMF, IOTA, OECD (2024), VITARA Reference Guide: Organization, OECD Publishing, Paris, https://doi.org/10.1787/ab075e83-en.
[7] CIAT, IMF, IOTA, OECD (2023), VITARA Reference Guide: Strategic Management, International Monetary Fund, Washington, DC, https://doi.org/10.5089/9798400223488.069.
[1] OECD (2023), Tax Administration 2023: Comparative Information on OECD and other Advanced and Emerging Economies, OECD Publishing, Paris, https://doi.org/10.1787/900b6382-en.
[3] OECD (2021), Behavioural Insights for Better Tax Administration: A Brief Guide, OECD Publishing, Paris, https://doi.org/10.1787/582c283e-en.
[4] OECD (2021), Tax Administration 2021: Comparative Information on OECD and other Advanced and Emerging Economies, OECD Publishing, Paris, https://doi.org/10.1787/cef472b9-en.
[10] OECD (2021), “Tax administration: Towards sustainable remote working in a post COVID-19 environment”, OECD Policy Responses to Coronavirus (COVID-19), OECD Publishing, Paris, https://doi.org/10.1787/fdc0844d-en.
[2] OECD (2017), Tax Administration 2017: Comparative Information on OECD and Other Advanced and Emerging Economies, OECD Publishing, Paris, https://doi.org/10.1787/tax_admin-2017-en.