Director General of Taxes Bimo Wijayanto recently announced that Indonesia’s tax buoyancy reached 2.25% in the first half of 2026, a significant improvement from -0.1% in the previous year. The figure also marks a sharp turnaround from -7.84% recorded in 2020.
The 2026 tax buoyancy becomes a tax revenue quality improvement indicator. The value suggests that, within the same period, tax revenue is now growing faster than the economy itself. But what exactly is tax buoyancy, and how does it relate to Indonesia’s tax ratio and the overall effectiveness of its tax system?
What Is Tax Buoyancy?
In simple terms, tax buoyancy measures how responsive tax revenue is to changes in gross domestic product (GDP). It shows how much tax revenue rises or falls as economic activity expands or contracts.
Unlike other indicators that measure only the impact of economic growth, tax buoyancy also captures the effects of government tax policies. These include tax rate adjustments, tax base expansion, incentives, administrative reforms, and other fiscal measures.
Since it reflects both economic conditions and policy changes, tax buoyancy provides a broader picture of how effectively a country’s tax system converts economic growth into state revenue.
The indicator is calculated by comparing the percentage change in tax revenue with the percentage change in GDP. A value greater than 1 indicates that tax revenue is growing faster than the economy, while a value below 1 suggests that tax revenue is lagging behind economic growth.
For instance, if the economy grows by 5% while tax revenue increases by 7%, the resulting tax buoyancy is 1.4. In other words, every 1% increase in economic activity generates a 1.4% increase in tax revenue.
The Economic Theory
Tax buoyancy is closely linked to the concept of elasticity in economics, which measures how one variable responds to changes in another. In terms of taxation, it reflects how tax revenue responds to fluctuations in economic activity.
The more responsive tax revenue is to economic growth, the higher a country’s tax buoyancy. It indicates that the tax system is more effective at translating economic expansion into additional state revenue.
Tax buoyancy is also related to the Keynesian theory of automatic fiscal stabilizers. During periods of economic growth, household incomes, corporate profits, and consumer spending generally increase, automatically expanding the tax base and boosting tax collections.
Conversely, when economic activity slows, tax revenue naturally declines as business activity falls. This automatic adjustment helps stabilize the economy throughout the business cycle.
The concept is also associated with the theory of optimal taxation, which emphasizes that an effective tax system should balance revenue generation with efficiency, fairness, and minimal distortion to economic activity.
In addition, it is closely related to tax capacity, which refers to a country’s ability to raise tax revenue. International organizations such as the International Monetary Fund (IMF) and the World Bank frequently use this concept to assess the effectiveness of national tax systems based on their economic potential.
Tax Buoyancy vs Tax Elasticity
Although often discussed together and closely linked, tax buoyancy and tax elasticity measure different aspects of tax performance.
Tax elasticity measures how tax revenue changes solely as a result of economic growth, excluding the effects of tax policy shifts. It therefore reflects the tax system’s inherent responsiveness to economic activity.
Tax buoyancy, on the other hand, captures the combined impact of tax revenue generation, including tax reforms, changes in tax rates, tax incentives, expansion of the tax base, and improvements in tax administration.
For this reason, tax buoyancy generally provides a more comprehensive picture of a country’s actual tax revenue performance.
Tax Buoyancy and Fiscal Policy
Tax buoyancy is an important fiscal indicator as it demonstrates how effectively a tax system converts economic growth into higher state revenue.
In preparing the state budget, policymakers use tax buoyancy to estimate future tax revenue based on projected economic growth. The indicator is also useful for evaluating the effectiveness of tax reforms, including digitalization initiatives, tax base expansion, and efforts to improve taxpayer compliance.
At the international level, organizations such as the IMF, OECD, and World Bank also use tax buoyancy to compare the performance of tax systems across countries.
Indonesia’s Tax Ratio
Although closely related, tax buoyancy and tax ratio measure different aspects of tax performance. The tax ratio represents the proportion of tax revenue relative to GDP within a specific period, indicating the overall tax contribution to the economy.
Tax buoyancy, meanwhile, measures the rate at which tax revenue grows relative to economic growth. When tax revenue increases faster than GDP, the tax ratio typically improves. Contrarily, if tax revenue grows more slowly than the economy, the tax ratio may stagnate or decline.
As a result, improving Indonesia’s tax ratio cannot solely rely on higher tax rates. Sustainable progress also depends on broadening the tax base, enhancing taxpayer compliance, modernizing tax administration, and applying institutional reforms that improve tax buoyancy over the long term.
Tax Buoyancy Outlook for Indonesia
International experience shows that strong tax buoyancy is driven not only by tax rates but also by the quality of a country’s tax system. Economies with a modern tax administration, broad tax bases, and high levels of voluntary compliance tend to be better positioned to increase tax revenue as their economies grow.
For Indonesia, the improvement in tax buoyancy represents an encouraging sign that tax reforms are delivering results. Sustained economic growth must be supported by an effective tax system to convert economic expansion into state revenue.
Also Read:
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DGT Regulation Number 11 of 2025
Breaking Down the Article 21 Withholding Tax Provisions