Purpose

The study analyzes the influence of corporate governance and ownership concentration levels on the cost of equity. Further, the authors extend the literature by investigating the moderating effect of ownership concentration levels (i.e. at 5%, 10% and 20%) on the relationship between corporate governance and the cost of equity.

Design/methodology/approach

The study applies several robust panel regression techniques to a sample of 114 active non-financial companies listed on the Pakistan Stock Exchange from 2011 to 2016. Corporate governance was measured through a unique index comprising 30 governance attributes. The cost of equity was measured through the capital asset pricing model. Further, the authors construct three variables for ownership concentration levels, i.e. at 5%, 10% and 20%. To address the endogeneity problem, the one-lagged variable model and GMM approaches were also applied.

Findings

The results indicate that better corporate governance reduces the cost of equity, while ownership concentration at high thresholds would increase the cost of equity. Further, the authors find that ownership concentration at the 20% threshold moderates the relationship between corporate governance and the cost of equity. Thus, the authors argue that firms can minimize the risk faced by shareholders by implementing substantive corporate governance mechanisms. In addition, effective corporate governance mechanisms at high ownership concentration levels are imperative for managing the cost of equity.

Originality/value

The study reports novel evidence that ownership concentration at a high threshold moderates the effect of corporate governance on the cost of equity.

中文翻译：

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公司治理与股权成本：所有权集中度的调节作用

目的

研究分析了公司治理和股权集中度对股权成本的影响。此外，作者通过调查所有权集中度水平（即 5%、10% 和 20%）对公司治理与股权成本之间关系的调节作用扩展了文献。

设计/方法/途径

该研究对 2011 年至 2016 年在巴基斯坦证券交易所上市的 114 家活跃的非金融公司样本应用了几种稳健的面板回归技术。公司治理是通过一个包含 30 个治理属性的独特指数来衡量的。权益成本通过资本资产定价模型计量。此外，作者为所有权集中度构建了三个变量，即 5%、10% 和 20%。为了解决内生性问题，还应用了单滞后变量模型和 GMM 方法。

发现

结果表明，更好的公司治理会降低股权成本，而高门槛的所有权集中度会增加股权成本。此外，作者发现，20% 阈值的所有权集中度缓和了公司治理与股权成本之间的关系。因此，作者认为，公司可以通过实施实质性公司治理机制将股东面临的风险降至最低。此外，所有权高度集中的有效公司治理机制对于管理股权成本至关重要。

原创性/价值

该研究报告了新的证据，表明所有权集中度处于高阈值会缓和公司治理对股权成本的影响。