Which Families Benefited from the Recent Personal Income Tax Reform in Taiwan: Evidence from the Administrative Data

This paper examines the changes in vertical equity across different types of tax filing families during the span of a series of drastic personal income tax reforms in Taiwan. The newly enacted 2016 Taxpayer Rights Protection Act has brought unprecedented challenges to the tax authority's distributional goal and revenue stability. Utilizing the administrative tax return data collected by the Ministry of Finance's Fiscal Information Agency between 2016 and 2018, we show that while the income tax has contributed to improving equality in income distribution, the effects, however, were limited and even declined slightly in recent years. We also found that distributions of tax benefits are generally regressive, especially among itemized and special deductions. It is also shown that the personal exemption and the adjustments of basic living expenses provided comparably more relief to households with dependents than to those claiming no dependents. According to our two-parameter metric encompassing the usage rates and the tax-benefit distributions for each deduction, we found that itemized deductions and special deductions, in general, are regressive. Specifically, we calculate and compare different representative families' tax payments before and after the reform. While the tax reform has helped reduce many tax-filing families' tax liabilities, most tax benefits generated from the expansion of exemptions and deductions would likely be enjoyed by families with higher incomes. In a broader reform-minded context, the analysis cautions the tax authority in Taiwan and equity pursuing policy makers in other countries not to prioritize an overarching short-term equity goal over long-term revenue stabilization. Phasing out or capping some of the itemized deductions such as donations and special deductions related to discretionary purchasing decisions looks to be a promising reform path toward improving equity and restoring revenue stability.