本研究探討言論自由對企業租稅規避行為的影響，利用美國各州分階段實施反公眾參與的策略性濫訴法(Anti-Strategic Lawsuit Against Public Participation Laws, Anti-SLAPP Laws)作為外生制度衝擊。本文以1987年至2023年美國上市公司為樣本，採用多時點差異中的差異法(Staggered Difference-in-Differences, Staggered DID)進行實證分析。實證結果顯示，相較於未受Anti-SLAPP法影響的企業，總部所在州通過Anti-SLAPP法的企業租稅規避程度未呈現顯著變化，顯示資訊揭露所帶來的資訊透明度效果與風險揭露效果可能同時存在，使資訊環境改善未進一步改變企業的租稅規劃決策。敏感性分析採用替代性租稅規避估計方式後，結果仍具穩健性。最後，橫斷面分析顯示，Anti-SLAPP法對企業租稅規避的影響並未因經理人能力或內部資訊品質的不同而產生顯著差異。

This study examines the impact of free speech on corporate tax avoidance by exploiting the staggered adoption of Anti-Strategic Lawsuit Against Public Participation (Anti-SLAPP) laws across U.S. states as an exogenous institutional shock. Using a sample of publicly listed U.S. firms from 1987 to 2023, we employ a staggered difference-in-differences (Staggered DID) approach for empirical analysis. The results show that, relative to firms headquartered in states without Anti-SLAPP laws, firms headquartered in states that adopted Anti-SLAPP laws do not exhibit significant changes in tax avoidance. These findings suggest that the transparency effect and the risk disclosure effect associated with greater information disclosure may coexist and offset each other, such that improvements in the information environment do not lead firms to alter their tax planning decisions. The results remain robust when alternative measures of tax avoidance are employed. Finally, cross-sectional analyses indicate that the effect of Anti-SLAPP laws on corporate tax avoidance does not differ significantly with managerial ability or internal information quality.

American Institute of Certified Public Accountants (1987). National Commission on Fraudulent Reporting, Report of the National Commission on Fraudulent Financial Reporting, AICPA, New York, NY.
Badertscher, B. A., Katz, S. P., & Rego, S. O. (2013). The separation of ownership and control and corporate tax avoidance. Journal of accounting and economics, 56(2-3), 228–250.
Balakrishnan, K., Billings, M. B., Kelly, B., & Ljungqvist, A. (2014). Shaping liquidity: On the causal effects of voluntary disclosure. The Journal of Finance, 69(5), 2237–2278.
Boehmer, E., Jones, C. M., & Zhang, X. (2008). Which shorts are informed? The Journal of Finance, 63(2), 491–527.
Böke, J., Brau, B., Glaeser, S., & Jeong, J. (2024). Freedom of speech and employee disclosure. Available at SSRN 4904664.
Callaway, B., & Sant’Anna, P. H. (2021). Difference-in-differences with multiple time periods. Journal of econometrics, 225(2), 200–230.
Cen, L., Maydew, E. L., Zhang, L., & Zuo, L. (2017). Customer–supplier relationships and corporate tax avoidance. Journal of financial economics, 123(2), 377–394.
Cengiz, D., Dube, A., Lindner, A., & Zipperer, B. (2019). The effect of minimum wages on low-wage jobs. The quarterly journal of economics, 134(3), 1405–1454.
Chemmanur, T. J., Rajaiya, H., & Sheng, J. (2019). How does online employee ratings affect external firm financing? Evidence from Glassdoor. Evidence from Glassdoor (December 16, 2019).
Chen, S., Chen, X., Cheng, Q., & Shevlin, T. (2010). Are family firms more tax aggressive than non-family firms? Journal of financial economics, 95(1), 41–61.
Chen, S., Ma, H., Teng, H., & Wu, Q. (2022). Banking liberalization and corporate tax planning: Evidence from natural experiments. Journal of Corporate Finance, 76, 102264.
Chen, Z., Li, Q., & Li, Y. (2025). Freedom of Expression and Stock Price Crash Risk: Evidence from a Natural Experiment. The Journal of Law and Economics, 68(2), 387–430.
Dyck, A., Morse, A., & Zingales, L. (2010). Who blows the whistle on corporate fraud? The Journal of Finance, 65(6), 2213–2253.
Dyreng, S. D., Hanlon, M., & Maydew, E. L. (2008). Long‐run corporate tax avoidance. The accounting review, 83(1), 61–82.
Dyreng, S. D., Hanlon, M., & Maydew, E. L. (2010). The effects of executives on corporate tax avoidance. The accounting review, 85(4), 1163–1189.
Dyreng, S. D., Hanlon, M., & Maydew, E. L. (2019). When does tax avoidance result in tax uncertainty? The accounting review, 94(2), 179–203.
Dyreng, S. D., Hanlon, M., Maydew, E. L., & Thornock, J. R. (2017). Changes in corporate effective tax rates over the past 25 years. Journal of financial economics, 124(3), 441–463.
Easley, D., & O'hara, M. (2004). Information and the cost of capital. The Journal of Finance, 59(4), 1553–1583.
Edwards, A., Hutchens, M., & V. Persson, A. (2024). Third‐party reporting and cross‐border tax planning. Contemporary Accounting Research, 41(2), 1248–1283.
Edwards, A., Schwab, C., & Shevlin, T. (2016). Financial constraints and cash tax savings. The accounting review, 91(3), 859–881.
Fernández-Rodríguez, E., García-Fernández, R., & Martínez-Arias, A. (2021). Business and institutional determinants of Effective Tax Rate in emerging economies. Economic Modelling, 94, 692–702.
Francis, B. B., Sun, X., Weng, C.-H., & Wu, Q. (2022). Managerial ability and tax aggressiveness. China Accounting and Finance Review, 24(1), 53–75.
Gallemore, J., & Labro, E. (2015). The importance of the internal information environment for tax avoidance. Journal of accounting and economics, 60(1), 149–167.
Graham, J. R. (2003). Taxes and corporate finance: A review. The Review of Financial Studies, 16(4), 1075–1129.
Graham, J. R., Hanlon, M., Shevlin, T., & Shroff, N. (2014). Incentives for tax planning and avoidance: Evidence from the field. The accounting review, 89(3), 991–1023.
Green, T. C., Huang, R., Wen, Q., & Zhou, D. (2019). Crowdsourced employer reviews and stock returns. Journal of financial economics, 134(1), 236–251.
Griffin, P. A., Hong, H. A., Jung, B., & Moon, K. (2024). Does Free Speech Law Contribute to Voluntary Corporate CSR Disclosure? Empirical Evidence.
Grubert, H. (2003). Intangible income, intercompany transactions, income shifting, and the choice of location. National Tax Journal, 56(1), 221–242.
Guenther, D. A., Matsunaga, S. R., & Williams, B. M. (2017). Is tax avoidance related to firm risk? The accounting review, 92(1), 115–136.
Guernsey, S., Serfling, M., & Yan, C. (2025). When Speaking Freely Pays: Anti-SLAPP Laws and Firms' Cost of Equity. Available at SSRN 5356267.
Gupta, S., & Newberry, K. (1997). Determinants of the variability in corporate effective tax rates: Evidence from longitudinal data. Journal of accounting and public policy, 16(1), 1–34.
Hales, J., Moon Jr, J. R., & Swenson, L. A. (2018). A new era of voluntary disclosure? Empirical evidence on how employee postings on social media relate to future corporate disclosures. Accounting, Organizations and Society, 68, 88–108.
Hanlon, M., & Heitzman, S. (2010). A review of tax research. Journal of accounting and economics, 50(2-3), 127–178.
Hanlon, M., Maydew, E. L., & Saavedra, D. (2017). The taxman cometh: Does tax uncertainty affect corporate cash holdings? Review of Accounting Studies, 22(3), 1198–1228.
Hanlon, M., & Slemrod, J. (2009). What does tax aggressiveness signal? Evidence from stock price reactions to news about tax shelter involvement. Journal of Public economics, 93(1-2), 126–141.
Hartzler, S. (2006). Protecting informed public participation: anti-SLAPP law and the media defendant. Val. UL Rev., 41, 1235.
Hasan, M. M., Lobo, G. J., & Qiu, B. (2021). Organizational capital, corporate tax avoidance, and firm value. Journal of Corporate Finance, 70, 102050.
Hayek, F. (1945). American economic association. The American Economic Review, 35(4), 519–530.
Henry, E., Massel, N., & Towery, E. (2016). Increased tax disclosures and corporate tax avoidance. National Tax Journal, 69(4), 809–829.
Honaker, K., & Sharma, D. S. (2017). Does schedule UTP have uniform long-run effects on corporate tax planning? The journal of the American taxation association, 39(2), 63–79.
Hoopes, J. L., Mescall, D., & Pittman, J. A. (2012). Do IRS audits deter corporate tax avoidance? The accounting review, 87(5), 1603–1639.
Huseynov, F., & Klamm, B. K. (2012). Tax avoidance, tax management and corporate social responsibility. Journal of Corporate Finance, 18(4), 804–827.
Hutton, A. P., Marcus, A. J., & Tehranian, H. (2009). Opaque financial reports, R2, and crash risk. Journal of financial economics, 94(1), 67–86.
Jung, B., Wang, Y., Wei, S., & Zhang, J. I. (2021). Employees’ voluntary disclosures about business outlook and labor investment efficiency. Available at SSRN 3861033.
Kim, J. W., & Shi, Y. (2011). Voluntary disclosure and the cost of equity capital: Evidence from management earnings forecasts. Journal of accounting and public policy, 30(4), 348–366.
Lambert, R., Leuz, C., & Verrecchia, R. E. (2007). Accounting information, disclosure, and the cost of capital. Journal of Accounting Research, 45(2), 385–420.
Lang, M., Lins, K. V., & Maffett, M. (2012). Transparency, liquidity, and valuation: International evidence on when transparency matters most. Journal of Accounting Research, 50(3), 729–774.
Lee, J., Ng, S., Yoo, I. S., & Zhang, L. (2026). Freedom of Expression Protection and Corporate Concealment of Bad News: Evidence from State Anti‐SLAPP Laws. Journal of Accounting Research, 64(1), 365–415.
McGuire, S. T., Omer, T. C., & Wang, D. (2012). Tax avoidance: Does tax-specific industry expertise make a difference? The accounting review, 87(3), 975–1003.
Miller, G. S. (2006). The press as a watchdog for accounting fraud. Journal of Accounting Research, 44(5), 1001–1033.
Pring, G. W., & Canan, P. (1996). SLAPPs: Getting sued for speaking out. Temple University Press.
Rego, S. O. (2003). Tax‐avoidance activities of US multinational corporations. Contemporary Accounting Research, 20(4), 805–833.
Rego, S. O., & Wilson, R. (2012). Equity risk incentives and corporate tax aggressiveness. Journal of Accounting Research, 50(3), 775–810.
Shevlin, T., Thornock, J., & Williams, B. (2017). An examination of firms’ responses to tax forgiveness. Review of Accounting Studies, 22(2), 577–607.
Stickney, C. P., & McGee, V. E. (1982). Effective corporate tax rates the effect of size, capital intensity, leverage, and other factors. Journal of accounting and public policy, 1(2), 125–152.
Subrahmanyam, A., & Titman, S. (1999). The going‐public decision and the development of financial markets. The Journal of Finance, 54(3), 1045–1082.
Verrecchia, R. E. (2001). Essays on disclosure. Journal of accounting and economics, 32(1-3), 97–180.