Submitted by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-06-13T14:11:27Z No. of bitstreams: 1 SinvalBragadeFreitasTese2016.pdf: 706624 bytes, checksum: 578a2a771cd50a1b6f9bb8145d641ce3 (MD5) / Approved for entry into archive by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-06-13T14:11:38Z (GMT) No. of bitstreams: 1 SinvalBragadeFreitasTese2016.pdf: 706624 bytes, checksum: 578a2a771cd50a1b6f9bb8145d641ce3 (MD5) / Made available in DSpace on 2017-06-13T14:11:39Z (GMT). No. of bitstreams: 1 SinvalBragadeFreitasTese2016.pdf: 706624 bytes, checksum: 578a2a771cd50a1b6f9bb8145d641ce3 (MD5) Previous issue date: 2016-06-03 / In this paper rst we studied a family of functions de ned as Arrow-Debreu functions, which proved to contain the entire family of pseudo concave functions that appear in the literature. We show that the closures of the preferred sets are usually star shaped and when the e ective domain is convex these sets are also convex. Some existence results for the classical maximization problem are given for this family of functions. After this the concept of satiation a ordability opportunities in unbounded economies is introduced and shown that the hypothesis that there is no satiation a ordability opportunity de ned here is necessary and su cient condition for existence of solution for the consumer problem. Finally it is shown this hypothesis is a consequence of inconsequential arbitrage condition. / Neste trabalho estudamos primeiro uma fam??lia de fun????es de nidas como Fun????es de Arrow- Debreu, a qual provamos conter toda a fam??lia de fun????es pseudo c??ncavas que aparecem na literatura. Mostramos que os fechos dos conjuntos dos preferidos s??o, em geral, estrelados e quando o dom??nio efetivo ?? convexo esses conjuntos tamb??m s??o convexos. Alguns resultados de exist??ncia para o problema de maximiza????o cl??ssico s??o dados para essa fam??lia de fun????es. Em seguida, o conceito de oportunidades de acessibilidade saciada em economias n??o limitadas ?? introduzido e mostrado que a hip??tese de n??o exist??ncia de oportunidade de acessibilidade saciada aqui de nida ?? condi????o necess??ria e su ciente para que o problema do consumidor tenha solu????o. Finalmente ?? mostrado que essa hip??tese ?? consequ??ncia da condi????o de arbitragem inconsequente.