The current study aims to investigate the relationship between tax avoidance and firm risk in an emerging market called Iran. The study population consists of 400 observations and 80 companies listed on the Tehran Stock Exchange (TSE) over a five-year period during 2012 and 2016. The statistical model used in this study is a multivariate regression model; besides, the statistical technique used to test the hypotheses proposed in this research is panel data. The results showed that low effective tax rate (tax avoidance) is more consistent than the higher effective tax rate. Moreover, there is no significant relationship between tax avoidance and future tax rate volatility. The findings also proved that lower effective tax rates are positively associated with future stock price volatility. This implies that since Iranian firms have many financial problems because of economic sanctions, they have a tendency to delay the disclosure of bad news about their firms. Needless to say, when a huge number of negative news reaches its peak, they immediately will enter the market and lead to a remarkable fluctuation in stock prices.

Abstract
1. Introduction
2. Theoretical Framework and Literature Review
3. Research Methodology
    3.1. Research Models
4. Results
    4.1. Descriptive Statistics
    4.2. The Results of the First Hypothesis
    4.3. The Results of the Second Hypothesis
    4.4. The Results of the Third Hypothesis
5. Conclusion
References

• Mahdi SALEHI(Economics and Administrative Sciences, Ferdowsi University of Mashhad, Iran.) Corresponding Author
• Sharbanoo KHAZAEI(Economics and Administrative Sciences, Gaenat Branch, Islamic Azad University, Iran.)
• Hossein TARIGHI(Economics and Administrative Sciences, Attar Institute of Higher Education)