Processo de tomada de decisão do investidor individual brasileiro no mercado acionário nacional: um estudo exploratório enfocando o efeito disposição e os vieses da ancoragem e do excesso de confiança

• Autor(a) principal: Gomes, Felipe Bogéa
• Data de Publicação: 2007
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações do Mackenzie
• Texto Completo: http://dspace.mackenzie.br/handle/10899/23506
• topic: ancoragem; excesso de confiança; efeito disposição; finanças comportamentais; anchoring; overconfidence; disposition effect; behavioral finance; CNPQ::CIENCIAS SOCIAIS APLICADAS::ADMINISTRACAO::ADMINISTRACAO DE EMPRESAS

Among the fields of study of behavioral finance is the identification of how emotions and cognitive errors can influence the decision process of investors. Published works in experimental psychology and behavioral finance indicated the use of heuristics behavio rs and their consequent biases in the decision process of agents participating in the financial market. The current research aims to recognize possible cognitive illusions shown by the Brazilian individual investor in their decision process, and also wishes to obtain more information about these biases, relating the empirical results to the theories of beha vioral finance. With that in mind, this thesis proposes to answer the following questions: is there evidence of the disposition effect and of the biases of anchoring with insufficient adjustment and overconfidence in the decision process of the Brazilian investor? How could these behaviors be related to personal traits of investors? In order to analyze the decision process of investors, a specific research instrument was developed. It is a questionnaire composed of 38 questions, 27 of which relating to biases and 11 to personal traits of investors. The contact with the investors was made possible through a partnership with the National Institute of Investors (INI in the Portuguese acronym). The Institute invited its associates to participate in the research through email and indicated the website where the questionnaire was available. In this way, each investor accessed the website and filled out the questionnaire on line. A non-probabilistic sample was used, made up of investors from different states in Brazil. After the exclusion of non-valid questionnaires, there remained a sample of 512 individuals. The results of this research are evidence of the presence of the disposition effect, of anchoring with insufficient adjustment and of overconfidence, but they do not prove their connection to the personal characteristics of investors. The presence of cognitive illusions has been documented in several countries and situations. However, in Brazil, as far as we know, their presence in a sample made up of investors participating in the Brazilian stock market had not been identified yet. Therefore, the results obtained contribute to confirm evidence from other countries, showing that the Brazilian investor is also subject to such behavior. The failure to verify the relationship of the cognitive errors with the characteristics of investors permits us to suggest the use of other variables in future works since part of the literature finds evidence of these relationships in certain specific characteristics. Although the research instruments lack formal validation, they contribute to the establishment of simple, easily applicable instruments that may identify cognitive illusions detrimental to Brazilian investors.