세무위험과 기업위험 ―주가변동성, 시장베타 및 자본비용 측면에서―

This study empirically examine whether higher levels of tax risk are associated with increased firm risk, as perceived by investors in the capital market participants. Specifically, this study use market-based risk measure of one-year-ahead stock return volatility, market beta, and the cost of capital as proxies for firm risk. Recent literature in the overseas research examines tax risk. For examples, two studies, Hutchens and Rego(2015) and Guenther et al.(2017) examine the association between tax risk and one-year-ahead stock return volatility. Meanwhile, prior domestic research documents that tax avoidance increases firm risk measure of one-year-ahead stock return volatility (e.g., Kim and Kim 2016；Park 2017). However, what is unknown in the domestic research is whether firms with relatively high tax risk, do bear significantly greater firm risk (i.e., market-based risk measures) than firms that have lower tax risk. Therefore, I examine whether tax risk provides incremental information about firms risk, which have been less explored in prior domestic research. In particular, I examine whether tax risk, compared to tax avoidance, provides incremental information about firm risk. For the analysis, I examine the association between firm risk and tax risk. Then tax risk is calculated as the standard deviation of annual CASH (GAAP) ETRs for five-year (t to t－4) period prior to and including the current year (e.g., Hutchens and Rego 2015；Guenther et al. 2017). Following Dyreng et al.(2008), tax avoidance, which I calculate the CASH (GAAP) ETRs as the ratio of the sum of the cash taxes paid (tax expense) divided by the sum of pre-tax income measured over the five-year, t to t－4. in regression analyses I multiply CASH (GAAP) ETRs by negative one, so that larger values indicate greater corporate tax avoidance. For my empirical tests, I use a sample of firms with positive pretax income and ETR data from 1999 through 2016 to construct four effective tax rate measures. This paper predict that higher values for each of tax risk/tax avoidance metrics are associated with investors’ assessment of increased firm risk. I sample covers KOSPI and KOSDAQ listed firms with fiscal year-end from 2003 to 2016. The empirical findings of this study are following. First, after controlling for several factors as well as tax avoidance that affect firm risk, on average, I find that firms with relatively high tax risk significantly increase in subsequent stock return volatility, market beta, and cost of capital. Thus, I find predictable variation in stock return volatility, beta, and cost of capital related to the properties of tax risk. This is, firms with higher values of tax risk as the volatility of firms’ annual CASH ETRs and GAAP ETRs would be perceived by investors as having more uncertain future cash flows. In particular, The results support the notion that tax risk can provide additional information about uncertainty regarding a firm’s future cash flows, as reflected in the market-based risk measures of firm risk. future after cash flows predictability. In contrast, I find that the positive relation between tax avoidance and subsequent stock return volatility and market beta, whereas I find no significant positive association between tax avoidance and cost of capital. Second, I find that consistently positive and significant relation between tax risk and subsequent stock return volatility, market beta, and cost of capital, when this study measure tax risk as firm with relatively high tax risk is an indicator variable set equal to one for firms in the top quintile and zero otherwise instead of continuous variable of tax risk. Lastly, these results suggest that tax risk proxies is positively associated with subsequent stock return volatility, market beta, and cost of capital regardless of financial reporting quality (i.e., accruals quality). In sum, this study provide robust evidence that CASH ETRs volatility and GAAP ETRs volatility are consistently, positively associated with all three measures of firm risk. Thus, I conclude that tax risk measure using CASH ETRs volatility and GAAP ETRs volatility capture investors uncertainty about a firm’s future cash flows. Therefore, this paper increases our understanding of which tax risk capture overall firm risk that lead to assessments by investors in the capital market. Also, these results provide evidence that tax risk provide incremental information about future predictability beyond tax avoidance even when controlling for the variance of pretax earnings and other observable firm characteristics associated with market risk. It should also be helpful to practitioners, regulators, tax authorities, and policymakers in determining whether greater tax risk increased firm risk, as perceived by investors in the capital market.