La revisione esterna dei bilanci di sostenibilità. Analisi delle caratteristiche ed implicazioni per il costo del capitale

ABSTRACT: (ASSURANCE STATEMENT PRACTICES IN STAND-ALONE CORPORATE SOCIAL RESPONSIBILITY REPORTS). The paper deals with the external assurance of the environmental, social and sustainability stand-alone report, by focusing on its characteristics and its market consequences. More specifically, it aims at exploring to what extent the third-party assurance of corporate environmental and sustainability reports results in a lower cost of capital through an enhanced credibility of the disclosed information. The empirical investigation is conducted on a sample of 118 European oil companies. This is an ideal setting since they are under a great pressure for disclosing credible information about corporate social responsibility reporting due to the high risk of environmental abuses. The empirical analysis is developed in two steps. In the first step, a multivariate analysis is conducted in order to assess the existence and the nature of the relation between the implied cost of capital, as measured by the PEG ratio, and the external assurance of corporate social responsibility disclosure. In the second step, a content analysis of the assurance statement in corporate social responsibility disclosure, has been carried out. In this perspective, the paper not only aims at investigating the market consequences of the external assurance of environmental, social and sustainability stand-alone reports, but it also explores those features that affect its quality. The findings reveal the existence of a negative relation between the presence of an assurance statement for corporate social responsibility stand-alone reports and the cost of capital, suggesting that the external assurance increases the credibility of the voluntary and not easily verifiable information, thus contributing to the reduction of the information asymmetries and the transaction costs in the capital market. When shifting the focus on the features of the assurance statement practice, it emerges that the quality of the external assurance is high, although there are some aspects that need further improvements. This article contributes to the recent academic debate on the external assurance of corporate social responsibility in several ways. First of all, it provides empirical evidence supporting the field of research that recognizes the external assurance as a mean to enhance the disclosure credibility. Second, it provides a better understanding of the relation between the cost of capital and voluntary, while not verifiable disclosure. Third, it shows under what condition the corporate social responsibility reporting can be relevant for the capital market participants. From a practical point of view, this study can be of help for standard setters in their regulatory activity concerning the external assurance of corporate social responsibility stand-alone reports.

KEYWORDS: Corporate social responsibility reports, External assurance, Cost of Capital