본 연구는 조세회피가 미래 세무불확실성을 증가시키는지를 실증분석하였다. 선행연구인 Guenther et al.(2017)은 조세회피와 미래 현금흐름의 불확실성을 주로 투자자 측면의 차기 주가변동성으로 살펴본 반면, 본 연구는 조세회피와 미래 현금흐름의 변동성과의 관계를 직접 분석한다는 점에서 차별화된다. 본 연구는 조세회피를 Dyreng et al.(2008)에 따라 과거 5년간의 CASH ETR과 GAAP ETR로, 미래 현금흐름의 불확실성은 미래 5년간의 영업현금흐름 또는 회계이익의 변동성으로, 미래 세무불확실성은 CASH ETR과 GAAP ETR의 미래 5년간 변동성으로 측정하였다. 표본은 1998년부터 2016년까지 12월 결산 상장기업 중 금융업을 제외한 6,119개 기업/연 자료이다. 실증분석 결과는 첫째, 높은 조세회피 성향과 미래 영업현금흐름의 변동성 간에는 관련성이 나타나지 않았으나, 높은 조세회피 성향과 미래 회계이익의 변동성 간에 양(+)의 관계가 나타났다. 둘째, 높은 조세회피 성향은 미래 CASH ETR보다 미래 GAAP ETR의 변동성과 양(+)의 관계가 나타났다. 또한 추가분석에 따르면, 높은 조세회피 성향과 미래 과세소득의 변동성 및 미래 법인세부담액의 변동성은 유의한 음(-)의 관계가 나타났다. 셋째, 높은 조세회피의 성향은 미래에도 지속성이 높은 것으로 나타났다. 본 연구는 국내 상장기업에서 조세회피 성향이 높은 기업은 미래 회계이익의 변동성을 증가시키고, 미래 GAAP ETR의 변동성을 증가시키지만, 현재의 높은 조세회피 성향은 미래에도 과세소득의 변동성이나 법인세부담액의 변동성을 더 감소시키는 것으로 나타났고, 또한 미래 낮은 유효세율과도 양(+)의 관계로 나타나 지속성이 있음을 보여주었다는데 의미가 있다. 이러한 본 연구의 발견은 관련 연구에 추가적인 증거를 제공할 뿐만 아니라 조세회피 성향과 미래 세무불확실성과의 관계에 관심이 있는 세무당국이나 정책입안자들에게도 유익한 시사점을 줄 것으로 기대된다.
This study investigates whether the relation between tax avoidance and tax uncertainty regarding the firm’s future cash flows. Specifically, we examine whether low long-run effective tax rates are associated with greater uncertainty regarding the firm’s overall future cash flows. We also examine whether low effective tax rates have a higher degree of tax-related uncertainty because tax avoidance increases uncertainty regarding the firm’s future effective tax rates. Furthermore, we examine whether low effective tax rates are more persistent than high tax effective tax rates regarding the firm’s future volatility of taxable income as well as the volatility of cash tax paid. Our sample begins with all observations from 1998 to 2016 with available data in Korean Stock Exchange Market. This study sample covers KOSPI and KOSDAQ listed firms in non-financial industries with fiscal year-end in December from 2003 to 2011 period, our main sample consists of 6,119 firm-year observations. We document several findings. First, we do not find evidence that tax avoidance is associated with greater future volatility of cash flows from operation, where we find evidence that tax avoidance are positively associated with future after-tax volatility of earnings as well as future volatility of pre-tax earnings. This result suggests that a lower effective tax rate (aggressive tax avoidance) is associated with greater future earnings uncertainty. While, we fail find that a positive and significant association between tax avoidance and future volatility of cash flows, which is asserted in prior studies. Second, we find evidence that low effective tax rates tend to be more increases uncertainty regarding the firm’s future effective tax rates is positively associated with future volatility of GAAP effective tax rates (ETRs). Consistent with our predictions, we find low ETRs tend to be more persistent. Lastly, we find that low ETRs are more persistent than higher ETRs. This finding is consistent with Guenther et al. (2017). In summary, we provide evidence that tax avoidance is associated with greater future volatility of earnings than future volatility of cash flows from operation. We also provide evidence that tax avoidance is associated with greater future volatility of GAAP ETRs than future volatility of cash ETRs. Thus, in contrast, the results for cash ETR volatility are independent of tax avoidance. Additionally, we provide evidence that tax avoidance is associated with lower future volatility of taxable income as well as future volatility of cash tax payments. Therefore, we document that firms with higher tax avoidance have more persistent than firms with lower tax avoidance. In that sense, our study should be of interest to researchers that examine corporate tax avoidance practices and the extent to which capital market participants understand the implications of tax uncertainty. It should also be helpful to academics, as well as investors, regulators, tax authorities, and policymakers in determining whether or not greater tax avoidance increases uncertainty about a firm’s future cash flows or earnings, future effective tax rates, and future cash tax payments.