Introduction: Both accountants and financial economists and financial management have devoted considerable attention to the impact of governance structures. The accounting literature documents that these factors have a substantial impact on earnings management, while the finance literature shows that they likewise affect financial performance. Consistent with past research, our paper is similar to Black (2001) and Garay and Gonzalez (2008), who tested the relation between corporate governance and firm value in Russia and Venezuela as transition economies characterized by weak investor protection. The evidence we show here adds to the growing literature worldwide that indicates that firms can differentiate themselves by adopting better corporate governance practices and policies. That is, even in a weak investor protection environment, firms can increase their market value by adopting good corporate governance measures ....

This paper addresses whether and how the Sarbanes-Oxley Act of 2002 (SOX) affects SHAREHOLDER wealth (firm value) by focusing on the trade-off between improved corporate governance leading to a lower cost of capital and increased managerial compliance costs of regulations. We use an analytical model of solving the management utility maximization function and the change in stock prices in response to SOX regulations. We tested our analytical model by empirically investigating financial restatements in the pre and post-SOX.We conclude that all public companies can benefit from regulatory reforms, but the net effects vary across firms depending on investors’ perception about a firm’s governance quality before regulatory reforms and the required managerial compliance costs. Our analytical model also generates new predictions about management compliance behavior, which we test empirically by investigating restatements of financial statements.The model has policy implications by addressing cost-benefit of initiatives taken to improve US capital markets’ global competitiveness and they impacts on managerial compliance behavior. Our results may be relevant to regulators and public companies in Iran as the government has promoted a series of deregulation and privatization initiatives.Our model attempts to reconcile mixed empirical results of related studies pertaining to the effects of SOX on stock prices.

Strength measurement of rock requires testing that must be carried out on test specimens with particular sizes in order to fulfill testing standards or suggested methods. Often, the coring process breaks up the weaker core pieces, and they are too small to be used in either index tests or conventional strength tests such as point load index (Is) and Brazilian tensile strength (BTS). One of the index tests to indirectly determine the rock strength is the BLOCK punch index (BPI) test, which requires flat disc specimens without special treatment. This study aimed to evaluate the applicability of the BPI test for predicting the uniaxial compressive strength (UCS), BTS and IS of the sandstones by empirical equations. Also, we have compared the performance of the BPI and IS for predicting the UCS and BTS. It was experimentally shown that BPI is a reliable method for predicting the UCS, BTS and Is of the sandstones under study. Moreover, the results indicate that BPI could be utilized with same importance as Is for predicting the UCS, while predicting the BTS by Is appears to be more reliable than BPI.

The stock market plays an important role in the economic development of countries. Network analysis is one of the latest methods in analyzing the stock market. It is a new concept for a macro view of the whole market in quantitative science literature. Therefore, this research analyzes the available SHAREHOLDER network in the Tehran Stock Exchange from 2013 to 2017. This research is based on a type of data collected and analyzed is quantitative research. And, its’ type is network analysis. The research results indicate that many of SHAREHOLDERs are connected to each other, although a class structure governs their relations. Some of the SHAREHOLDERs, in comparison with others, have a better position. Having a better position caused them to encounter fewer mediators in gaining access to other SHAREHOLDERs, and also easier access to available resources. The SHAREHOLDERs’ ability in gaining access to information through the cluster of network members enhances too. Therefore, it is claimed that these SHAREHOLDERs can play the role of key actors in the governing structure. Also, the results of the Pareto distribution indicate that the distribution of power among the SHAREHOLDERs is approximately 25/75, that is, 75 per cent of the strength in the hands of 25 per cent of the SHAREHOLDERs.