台灣異質性家戶結構所得稅影響差異之實證研究與政策分析

Abstract

本文以家戶異質性與租稅影響為研究重點，首先對不同家戶結構所關聯的不同所得稅效應進行了實證研究，然後分析了對家戶異質性有所考量的所得稅政策。本文在實證研究和政策分析兩方面都在一定程度上填補了台灣在該議題上的研究空白。本研究採用了台灣中央研究院提供的「家庭收支調查」數據。數據中的樣本根據家戶類型代碼表分為兩組：單身家戶和已婚家戶，以探討單身家戶與已婚家戶面臨的所得稅影響差異。本文先後采用了多元線性回歸和非線性最小二乘法來估計參數 λ 和 τ。λ 用於確定一個經濟體的平均稅收水平。 τ 則描述累進狀況。這兩個參數一起決定了所得稅的性質和轉移支付框架。最終結果表明，所得稅對所有家戶結構都是累進的，稅收政策具有再分配效果。以非線性模型結果來説：在同等收入水平下，已婚家戶面臨的累進稅率更高，但他們的稅後收入可能高於單身家戶。為了進一步補充上述結果並反映現實，本文詳細介紹了台灣 「分開申報政策 」的實施情況，並將其與美國的制度進行了比較，對比了兩種制度的總體統計參數。

This paper focuses on household heterogeneity and tax impact, initially conducting an empirical study on the different income tax effects associated with various household structures, then analyzing income tax policies that consider household heterogeneity. To a certain extent, this paper fills the research gap in Taiwan on this topic, both in terms of empirical research and policy analysis. This research utilizes data from the 「Survey of Family Income and Expenditure」 provided by Academia Sinica of Taiwan. The sample in the data was categorized into two groups based on the family Type codebook: single households and married households, to explore the differences in income tax impact faced by single households versus married households. This paper employs both multiple linear regression and nonlinear least squares methods to estimate the two parameters λ and τ. λ is to determine the average level of taxation in an economy. τ describes the progressivity status. The two parameters define the nature of income tax and the transfer schedule. The final results indicate that income tax is progressive for all household structures, and the tax policy has redistributive effects. Regarding the results of the nonlinear model: at equivalent income levels, married households face a more progressive tax rate, yet they possibly have higher after-tax income than single households. To further supplement the above results and reflect reality, this paper provides a detailed account of the implementation of the 「separating filing policy」 in Taiwan, compares it with the system in the United States, and contrasts the macro statistical parameters of the two systems.