조세회피는 일반적으로 세후 현금흐름이 늘어나므로 기업가치가 증가한다는 긍정적인 효과가 있다. 그러나 소유와 경영이 분리된 환경에서 조세회피는 대리인 비용을 발생시키고, 기업의 투명성을 하락시킬 수 있기 때문에 자본시장에서 기업가치가 할인되어 평가되는 부정적인 효과도 있다. 조세회피 연구에서 조세회피의 비용에 대한 문제는 상대적으로 소홀하게 다루어져 왔다. 그러나 최근 대리인 관점의 연구들은 조세회피로 발생하는 비용이 중요하고, 세금비용 뿐만 아니라 비세금비용의 크기에 따라 조세회피와 기업가치의 관계가 중요한 영향을 받는다는 결과들을 보여주고 있다. 조세회피 때문에 발생하는 대리인 비용과 기업투명성 하락과 같은 비세금비용이 증가하는 경우 조세회피와 기업가치의 관계가 부정적인 관계로 나타날 수 있을 것으로 예상된다. 한편 기업지배구조는 조세회피와 기업가치의 관계를 조정하는 역할을 수행하여 조세회피의 기업가치에 대한 부정적인 효과를 완화할 것으로 예상된다. 본 연구는 조세회피와 기업가치의 관계와 기업지배구조의 역할에 대해 검증하였다. 조세회피는 측정오차를 줄이기 위해 (현금)유효법인세율, 산업.규모조정 (현금)유효법인세율, 재량적 재무이익과 세무이익의 차이(Book-Tax Differences: BTD)와 자본단위당 세금보조금 등을 이용한 여섯 가지 대용치를 사용하였고, 기업가치는 토빈Q로 측정하였다. 기업지배구조는 선행연구에서 사용된 기업지배구조 변수 중에서 요인분석을 이용하여 이사회의 독립성, 대주주지분율, 기관투자자 지분율, 외국인지분율을 선정하였다. 분석기간은 2001년부터 2010년까지이고, 비금융 상장기업을 대상으로 분석하였다. 본 연구의 분석결과에 따르면 조세회피와 기업가치는 음(-)의 관계로 나타났다. 대리인 관점의 예상과 같이 조세회피의 비세금비용이 상당히 크기 때문에 세금절감효과를 초과하여 기업가치에 부정적인 영향을 주는 것으로 추정된다. 그리고 기업지배구조가 우수할수록 조세회피와 기업가치의 부정적인 관계는 완화되는 것으로 나타났다. 기업지배구조가 조세회피의 부정적인 효과를 감소시키는 역할을 하고 있다는 점을 보여주고 있다. 본 연구는 조세회피가 기업가치에 긍정적이라는 선행연구와 달리 우리나라에서 조세회피가 기업가치에 부정적인 영향을 줄 수 있다는 실증적인 증거를 다양한 조세회피 측정치를 이용하여 제시하였고, 이런 결과는 조세회피로 유보된 자원이 효율적으로 사용되지 않는다는 점을 보여주고 있다. 그리고 기업지배구조가 우수한 기업은 조세회피와 기업가치의 부정적인 관계를 완화할 수 있다는 점을 보여 기업지배구조의 효과에 대한 실증적인 증거를 추가하였다는 점에서 본 연구의 의의를 찾을 수 있다.

This study investigates the relation between tax avoidance and firm value and the extent to which the relation is affected by corporate governance. Tax avoidance reduces resources that should transfer from shareholders to the government, so it might arguably make firm value increase. Corporate tax avoidance brings with it significant costs and benefits for management and shareholders. The relative difference between costs and benefits of corporate tax avoidance influences on the relation between tax avoidance and firm value. There are two alternative views on tax avoidance in empirical tax research in general. Traditionally, the first view is that managers undertake tax avoidance for the purpose of reducing corporate tax obligations only. From this view, tax avoidance is considered a value enhancing activities. Although this view also entails the potential costs of tax avoidance, the costs mainly include direct costs, such as the potential risk of detection by tax authorities. This view implicitly assumes that the costs of tax avoidance are less important and specifically, indirect costs are insignificant. The agency perspective of tax avoidance, however, suggests that opportunistic managers may exploit the obfuscatory nature of tax avoidance to mask rent extraction. The separation of ownership and control in corporate makes the agency costs related to tax avoidance increase. From the agency perspective, there are potential agency costs in the form of rent extraction by managers, reputational costs, political costs, and corporate transparency problem. These non-tax costs may offset the increasing value of corporate tax avoidance. The relation between tax avoidance and firm value depends on the difference between costs and benefits of tax avoidance. The previous literature has expected to enhance firm value by tax avoidance under the traditional view; however, from the agency perspective, the non-tax costs have increased and they have a detrimental impact on firm value in the recent research. Tax avoidance activities can create opportunities for the rent extraction by the manager. The corporate transparency could deteriorate by tax avoidance and it might bring with information asymmetry and higher cost of capital. Considering the above arguments and evidence, we put forth an alternative idea that tax avoidance has the negative relation with firm value at some points. It is important to understand what role corporate governance structure plays in the monitoring and control of corporate tax avoidance. This study, in this respect, suggests that corporate governance plays the mediating role in corporate tax avoidance. In this paper, we defined tax avoidance as the reduction of explicit tax payments over time through all means of income reported to shareholders (Dyreng et al. 2008). To measure tax avoidance, we use CASH ETR, GAAP ETR, Adj CASH, Adj GAAP, discretionary BTD, and TSE. CASH ETR measured by taxes paid divided by pretax income, and Adj CASH is the firm`s industry size CASH ETR less the firm`s CASH ETR. GAAP ETR measured by tax expense divided by pretax income, and Adj GAAP is the firm`s industry size GAAP ETR less the firm`s CASH ETR. Discretionary BTD is in Desai and Dharmapala(2006), and TSE is pretax income multiplied statutory tax rate less tax expense divided by lagged equity. The average CASH ETR is 0.255 and GAAP ETR is 0.267 in our sample. CASH ETR is lower than GAAP ETR. Pearson correlations between tax avoidance measures have a generally positive relation when we adjusted CASH ETR and GAAP ETR multiplied (-1). To test our hypotheses, we regressed firm value on tax avoidance variables and other control variables. To this end, this study employs CASH ETR, GAAP ETR, Adj CASH, Adj GAAP, discretionary BTD, and TSE as a proxy for tax avoidance and Tobin`s Q as a measure of firm value. Drawing on factor analysis to choose governance variables, this work focuses on these four governance dimensions based on arguments and evidence in previous literature that shows independence on the board and controlling shareholder`s portion, institutional holdings, and foreign investor ownership. The other financial variables used in the analyses are collected from KIS Value and DataGuide Pro database. Our sample consists of the firms listed on Korean Stock Exchange over the period of 2001 to 2010, and the sample size is 3,405 firm-year observations for CASH ETR. The empirical results of this study are as follows. First, we test the relation between tax avoidance and firm value. This result shows that firm value has negative associations with corporate tax avoidance contrary to most previous common consensus. It suggests that the cost of tax avoidance is more than the benefit of tax avoidance so that tax avoidance makes shareholder wealth decrease. Second, I examine how corporate governance impacts the association between tax avoidance and firm value, using interaction between tax avoidance and corporate governance. We find that investors place a value discount on tax avoidance but the discount decreases with the efficiency of corporate governance. This is consistent with the notion that strong corporate governance facilitates the monitoring of managerial actions and thus alleviates outside investors` concern about hidden agency costs associated with tax avoidance. The findings of this study are robust to various tax avoidance measures, in particular, and controls. This paper expands upon previous research in several ways. First, contrary to previous literature that tax avoidance is considered a value enhancing activities, the result of my study point to tax avoidance has the negative relation to firm value on average, thereby not effectively employing the reserved resource by tax avoidance. Second, the result provides corporate governance could reduce the negative relation between corporate tax avoidance and firm value. Therefore, we concluded by describing the findings of the agency perspective on tax avoidance and corporate governance roles in tax avoidance. Our evidence that tax avoidance could deteriorate firm value provides an important consideration in corporate tax decisions. We still have not sufficiently explained that how big costs of tax avoidance and what are the significant non-tax costs, why management does tax avoidance despite negative effects on firm value.