This paper studies the relation between earning volatility of firms and the future operating income predictability to define the effect of operating income volatility on investors’ expectations concerning future incomes. In other words, is there any possibility to predict future income using current volatility incomes? Logically it seems the present trend of companies will continue in future.For this purpose we considered the data of 120 companies which were admitted in Tehran Security Exchange Organization between 2003-2008. The examination was made based on regression analysis.The results indicate the meaningful and reverse relation between current volatility incomes and future operating income predictability. It also signifies that operating income predictability will increase In consequence of deducting accrual items from operating profits.

In this paper, we examine the effect of accounting conservatism on Earnings Persistence and Earnings distribution. This survey uses nonoperating accruals and adjusted market to book ratio as a proxies for accounting conservatism. We employ financial data of 98 firms listed in Tehran Stock Exchange. Correlation coefficients and linear regression analysis were used to test hypothesizes. The first hypothesis examines relationship between conservatism and Earnings distribution. This hypothesis is based on agency theory and predicts there is a negative relationship between these variables. Our empirical results support the first hypothesis. Second hypothesis is based on critics about conservatism and predicts more conservative Earnings are less persistent. According to our empirical tests, there are not enough supportive significant evidences to accept (also to reject) this hypothesis. This result implies that more researches are needed to shed light on relationship between conservatism and Earnings Persistence.

In this paper, we examine the effect of accounting conservatism on Earnings Persistence and pricing multiple on Earnings. One of the most obvious factors, among those that cause accounting Earnings to reverse over time, is accounting conservatism. By making more conservative accounting choices, a company faces mismatching between current-period revenues and future period expenses so that Earnings have more temporary components and become less persistent. This implies that Earnings are less persistent under more conservative accounting choices than under less conservative accounting choices. We hypothesize that more conservative Earnings are less persistent than less conservative Earnings. Moreover, according to Ohlson (1995) model, where price is expressed as a linear combination of equity book value and Earnings, the more (less) persistent Earnings obtain larger (smaller) pricing multiples. Thus, we hypothesize that the pricing multiple on more conservative Earnings is smaller than that on less conservative Earnings. Base on sample from 88 listed companies in Tehran stock exchange during the period of 1998-2007, our findings suggest more conservative Earnings are less persistent than less conservative Earnings and the pricing multiple on more conservative Earnings is smaller than that on less conservative Earnings.

The main objective of this study was to investigate the effect of income smoothing on investors reaction to Earnings Persistence of companies listed on the Stock Exchange in Tehran. The population of the study was companies listed on the Stock Exchange in Tehran, the sample size due to screening method and after removing outliers is equal to 118 companies. In this study, Earnings Persistence and income smoothing are considered as independent variables, and their impact on companies' reaction of investors is examined. In this study, the panel data is used with fixed and random effects, the results of the analysis of corporate data using multivariate regression at confidence level of 95% shows that the net income Persistence and operating profit Persistence have a direct impact on the reaction of investors. In addition, the results show that, income smoothing has a direct impact on relationship between investors and the net income Persistence and operating profit.

The aim of this study is to investigate the effect of Environmental Uncertainty on Earnings Persistence of listed Companies in Tehran Stock Exchange. The coefficient of variation (CV) of sales (scaled by total assets) to capture environmental uncertainty. For this purpose one hypothesis developed and data on the 108 companies in Tehran Stock Exchange for the period of 1390 to 1398 were analyzed. The number of data collected for this study is 972 years-firm. The regression panel data with fixed effects approach, reviews and tests. The results showed that the concentration of Environmental Uncertainty has significant negative impact on Earnings Response Coefficient. Therefore, the research results indicate that Environmental uncertainty, by creating serious restrictions for the company and Makes information asymmetry between management and stakeholders more acute it Earnings Persistence reduced.

In this paper the Persistence of abnormal changes in cash has been evaluated and then the Persistence of changes in cash and abnormal accruals has been compared. In addition, stock market efficiency with respect to characteristics of Earnings components Persistence has been investigated. To perform the research, first, the required data have been calculated, using cross- sectional multi-variable regression method. Then, final models have been estimated by pooled method. To estimate the models, we use financial information of 111 sample companies in the period of 2001 to 2010. The results indicate that there is not any difference between Persistence of negative abnormal changes and positive abnormal changes. Also abnormal accruals have greater Persistence than negative and positive abnormal changes. Another result indicates that the stock exchange market is inefficient to impound the Persistence of Earnings components.