The study captioned 'A Comparative Analysis of Tax Administration in Asia and the Pacific' shows that tax revenue as a percentage of gross domestic product (GDP) was highest (31.7%) in New Zealand in 2011. It was one of the lowest in India (9.7%).

The study notes: "collection is lowest in Indonesia, Cambodia, and India at around 10.0% of GDP."

The analysis is based on surveys of revenue bodies conducted in 2012 and 2013. The 22 economies in covered in the study are: Australia; Brunei Darussalam; Cambodia; the People's Republic of China (PRC); Hong Kong, China; India; Indonesia; Japan; the Republic of Korea; the Kyrgyz Republic; the Lao People's Democratic Republic; Malaysia; the Maldives; Mongolia; Myanmar; New Zealand; Papua New Guinea; the Philippines; Singapore; Taipei,China; Tajikistan; and Thailand.

Noting that effective human resources management is a key requirement for TAs, the study says that some revenue bodies, such as in Cambodia, India, Indonesia, the Philippines, and Myanmar, seem to be under-resourced and understaffed in proportion to the size of their populations. Moreover, the survey results suggest that some revenue bodies spend relatively few resources on human resources management, and performance management systems are lacking in a number of jurisdictions.

India, serving a population of 1.2 billion people or 31 million personal income taxpayers, has the most scarce tax office network with a total of 551 income tax offices, that is, 2.2 million people per office.

The People's Republic of China is the largest employer among comparator revenue bodies with 755,000 staff members. In contrast, India, which is the second-largest economy in terms of population, only employs 40,756 workers. The staff number in India is lower partly because it only captures the number of people employed to collect direct taxes. The second-largest employer in the Asia and Pacific region, for which data are available, is Japan with 56,261 full-time equivalent workers. Australia also employs a relatively large number of people given its population size. This partly reflects that a large proportion of the revenue body's workforce (16.5%) is engaged in nontax functions.

Only New Zealand, at 31.3%, has a larger share of staff working on nontax functions. In all other jurisdictions, almost all employees (more than 90%) or all employees are involved in the administration of national tax laws.

'Revenue bodies' survey responses suggest that the degree of autonomy given by governments to tax administrations to carry out their functions varies across the region. Australia, New Zealand, Papua New Guinea, and Singapore have the most independent tax administrations, with autonomy in human resources management, budget, and internal organization.

Certain TAs including India's direct & indirect tax TAs, CBDT and CBEC, can be classified as a directorate within the Ministry of Finance with limited autonomy.

As put by the study, "Increasing those revenue bodies' autonomy may help enhance their effectiveness and efficiency. Autonomy protects from political interference in day-to-day operations and gives tax administrations the flexibility in policy choices that they need to be able to respond to the rapidly changing challenges they face. Any extensive reforms, however, of the institutional arrangements between revenue bodies and ministries of finance cannot be carried out by the revenue body on its own, but require working with the government, civil service systems, and other public sector departments."

A significant finding of the study is that tax arrears tend to be a more frequent occurrence in developing economies than developed countries, reflecting lower enforcement capacity by tax administrations and taxpayer compliance.

The study says: "many factors influence the functioning of tax administrations, and the next step is to use the data collected from the surveys of revenue bodies in the region and OECD countries to determine which factors have a statistically significant influence on revenue bodies' performance."