회계이익과 과세소득의 차이(book－tax income difference)를 계산할 때 법인세비용차감전순이익을 회계이익으로 보는 것에 대해서는 이의가 없으나 과세소득으로서 어떤 것을 이용할 것인가에 대해서는 논란이 있으며 연구자마다 다른 측정치를 이용하고 있다. 과세소득을 어떻게 측정하는가에 따라 회계이익과 과세소득의 차이가 달라지고 연구의 결과가 달라질 수 있기 때문에 적절한 과세소득의 측정은 매우 중요하다. 본 연구에서는 우리나라의 연구에서 과세소득의 측정치로 많이 이용되는 각사업연도소득금액과 과세표준 및 추정과세소득을 이용하여 어떠한 측정치를 이용하는가에 따라 연구의 결과가 달라지는가를 알아보았다. 본 연구의 주요결과는 다음과 같다. 첫째, 과세소득으로 어떤 측정치를 이용하는가와 관계없이 전체기업을 대상으로 하는 경우에 회계이익과 과세소득 차이는 음의 값을 가지지만, 이익발생기업의 경우에는 양의 값을 갖고 손실발생기업의 경우에는 음의 값을 갖는 것으로 나타났다. 둘째, 과세소득으로 어떤 측정치를 이용하는가와 관계없이 회계이익과 과세소득 차이의 분포는 유사하고 세 가지 측정방법에 의한 과세소득간, 회계이익과 과세소득 차이간의 상관관계가 높은 것으로 나타났다. 셋째, 세 가지 측정방법을 이용한 회귀분석결과에서도 연구결과에 차이가 없는 것으로 나타났다. 결론적으로 본 연구의 결과는 회계이익과 과세소득 차이 계산시 과세소득으로 어떠한 측정치를 이용하든지 간에 결과가 유사하다는 것을 보여준다. 본 연구는 회계이익과 과세소득 차이의 계산방법이 연구결과에 영향을 미치지 않는다는 것을 보여줌으로써 그동안 다양한 회계이익과 과세소득 차이를 측정하여 연구한 연구들의 신뢰성에 문제가 없음을 보여주었다는 점에서 연구의 의의가 있다.

This study investigates whether a proxy of taxable income affects book－tax income difference. Most of studies use net income before tax expense as a book income and there is a unanimity about book income(financial accounting income) measure. But there are not unanimous agreements about tax income measure. An income during each fiscal year, tax base and estimated taxable income(measured by tax burden divided by tax rate) are alternatives of taxable income. This study analyzes three measures about taxable income(income during each fiscal year, tax base and estimated taxable income) and tests whether I will get different results depending on taxable income proxies using Korean data collected from 2000 to 2005. The main results are as follows. First, book－tax income difference of total sample and loss sample is negative but income sample is positive. This result is the same regardless of taxable income proxies. Second, regardless of taxable income proxies, the distribution of book－tax income difference is similar and correlation coefficient of three taxable income proxies is very high. Finally, regression results using three taxable income proxies are very similar. These results suggest that there is no differences in research output regardless of taxable income proxies and support that previous research results are reliable. The contributions of my research are to discuss about taxable income measure and to confirm that there is no problem on using of different proxies.

This study investigates whether a proxy of taxable income affects book－tax income difference. Most of studies use net income before tax expense as a book income and there is a unanimity about book income(financial accounting income) measure. But there are not unanimous agreements about tax income measure. An income during each fiscal year, tax base and estimated taxable income(measured by tax burden divided by tax rate) are alternatives of taxable income. This study analyzes three measures about taxable income(income during each fiscal year, tax base and estimated taxable income) and tests whether I will get different results depending on taxable income proxies using Korean data collected from 2000 to 2005. The main results are as follows. First, book－tax income difference of total sample and loss sample is negative but income sample is positive. This result is the same regardless of taxable income proxies. Second, regardless of taxable income proxies, the distribution of book－tax income difference is similar and correlation coefficient of three taxable income proxies is very high. Finally, regression results using three taxable income proxies are very similar. These results suggest that there is no differences in research output regardless of taxable income proxies and support that previous research results are reliable. The contributions of my research are to discuss about taxable income measure and to confirm that there is no problem on using of different proxies.

book income, taxable income, income during each fiscal year, tax base