The effect of differentiated levels of corporate governance on brazilian stock price: a study event to the announcement and adherence / O impacto do anúncio e da adesão das ações aos níveis diferenciados de governança corporativa no Brasil

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Corporate Governance practices? aim is to mitigate the problems originated from managerial agency issues, which arise when corporate ownership and its control are detached. In the end of the year 2000, Bovespa (São Paulo Stock Exchange) introduced the concept of differentiated corporate governance practices levels (Level 1, Level 2 or ?Novo Mercado?). In order to enter one of these levels the companies had to adhere to certain rules related to corporate governance practices. The goal of the dissertation herein is to analyze if Brazilian stocks? price is affected by the company?s decision to adopt Bovespa corporate governance practices differentiated levels, which are released via newspaper announcements or via adherence (through registration) to one of Bovespa?s corporate governance distinguished levels. Research encompasses the period between January 2001 and January 2006. The dissertation, therefore, seeks to detect the market information efficiency under the semi-strong format. The analysis is based on stocks? abnormal return, considering two distinct event dates: the first being the date of the adherence announcement in the newspapers, constituting the ?Announcement Date? sample; and, the second, Bovespa?s official registration date in one of the governance levels, constituting the ?Adherence Date? sample. Methodology consists of an event study to determine the average abnormal return ( AR ) and the average accumulated abnormal return (CAR) of the samples during the event?s window. Meanwhile, a multivariate model is developed in order to verify the impact of certain qualitative variables (ADR, ELE, PRIV and FAM) on the stocks? abnormal return. The Announcement Date sample results indicate a positive reaction from the market regarding the migration announcement to one of Bovespa?s differentiated corporate governance levels, especially in the proximity of the event date. In this scenario, the qualitative variables statistically did not present significant influence in the abnormal return. In the Adherence Date sample, however, there were no evidences of positive average abnormal returns and statistically significant throughout the event´s window. Moreover, the qualitative variables did not reveal statistically significant influence in the abnormal return. These results corroborate with the informational market efficiency theory in the semi-strong format, since the information concerning the migration to one of the levels had already been published in the Announcement Date (which took place before the official adherence date).

ASSUNTO(S)

eventos-estudos governança corporativa corporate governance event study

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