This work analyzes the effects that different information structures on the demand side of the market have on consumption decisions and the way prices are determined. We develop three theoretical models to address this issue in a systematic way. First, we focus our attention on the consumers' awareness, or lack thereof, of substitute products in the market and the strategic interaction between firms competing in prices and costly advertising in such an environment. We find that prior information held by consumers can drastically change the advertising equilibrium predictions. In particular, we provide sufficient conditions for the existence of three types of equilibria, in addition to one previously found in the literature, and provide a necessary condition for a fourth type of equilibrium. Additionally, we show that the effect of the resulting advertising strategies on the expected transaction price is qualitatively significant, although ambiguous when compared to the case of a newly formed market. We can establish, however, that the transaction price is increasing in the size of the smaller firm's captive market. In the second chapter, we study the optimal timing to buy a durable good with an embedded option to resell it at some point in the future, as well as its reservation price, where the agent faces Knightian uncertainty about the process generating the market prices. The problem is modeled as a stopping problem with multiple priors in continuous time with infinite horizon. We find that the direction of the change in the buyer's reservation price depends on the particular parametrization of the model. Furthermore, the change in the buying threshold due to an increase in ambiguity is greater as the fraction of the market at which the agent can resell the good decreases, and the value of the embedded option is decreasing in the perceived level of ambiguity. Finally, we introduce Knightian uncertainty to a model of price search by letting the consumers be ambiguous regarding the industry's cost of production. We characterize the equilibria of this game for high and low levels of the search cost and show that firms extract abnormal profits for low realizations of the marginal cost. Furthermore, we show that, as the search cost goes to zero, the equilibrium of the game under the low cost regime does not converge to the Bertrand marginal-cost pricing. Instead firms follow a mixed-strategy that includes all prices between the high and low production costs. / text

In the first chapter, I analyze the US banking industry in order to explain two facts. First, larger banks have lower but less volatile returns on loans compared to smaller banks over the years. Second, larger borrowers have better financial records, i.e. verifiable "hard" information, and they are more likely to match with larger banks, as documented by Berger et al.(2005). I show that these two facts can be explained using a segmented loan markets model with loan contracts between banks and borrowers. Moreover, I show that the difference between the banks returns is not due to diversification advantage of larger banks. Instead, it is because of the fact that larger banks can operate in both large and small loan markets, whereas small banks can only operate in small loans market. Therefore large banks are able to match with larger and less risky borrowers more frequently, which are less likely to default. Moreover, I take the model to infinite horizon allowing bank size to be endogenous to answer multiple policy questions about the future of small business finance and consolidation. I use the data set from the Consolidated Reports of Condition and Income provided by FDIC for 1984-2010 to motivate our research question and to estimate the model. My second chapter revisits the welfare cost of anticipated inflation in an incomplete markets environment where agents can substitute time for money by increasing their shopping frequency. Shopping activity provides an insurance channel to individuals against changes in the return on nominal balances through inflation as documented by Aguiar and Hurst (2007) and McKenzie and Schargrodsky (2011). In my model economy, a higher level of inflation affects people through two channels. First, it distorts the portfolio decision between real and nominal balances, second it redistributes wealth from those who hold more money to those who hold less. People, on average, respond to a higher level of inflation by increasing their price search activity, as they relative return on nominal balances goes down. I find that a 5 percent increase in inflation causes the welfare level go down by 2 percent if people are allowed to substitute time for money, and by 10 percent if we take this channel away from the model. Finally, in the third chapter, I compare the indirect measure of inflation expectations derived by Ireland (1996b) to the direct measures obtained from expectations surveys in multiple countries. Our results show that the inflation bounds calculated for US and UK data are more volatile than survey results, and are too narrow to contain them due to low standard errors in consumption growth series stemming from high persistence. For Chilean and Turkish cases, however, computed bound for inflation expectations seems to fit the survey results better. Out of three different surveys on inflation expectations in Turkey compared with the bounds computed using Turkish data, expectations obtained by the Consumer Tendency Survey fall within these bounds throughout the whole sample period. The success in the Turkish and Chilean cases can be attributed to the fact that volatility in the consumption series, whereas the failure in US and UK cases are most probably stemming from the fact that the current theoretical model is missing a risk-premium component. / text

This work is more than an analysis, it is an educational proposal in the form of class and extra class activities that culminate in an event which has been called the Seminar of Commercial and Financial Mathematics in Elementary Education II, a project that involves theoretical and Practices on Commercial and Financial Mathematics in Elementary School II in the municipality of Igaci (state of Alagoas). In the first part of the work, a bibliographical survey highlighting its importance and use in our daily life, we search for theoretical contributions in the studies of ANDRINI, in VASCONCELOS (2002), NETTO (1998), MONDAY, in LIGOCKI (2015), BIGODE 2002), CENTURIÓN, in JAKUBOVIC (2012). In the second part we make a brief explanation of the topics covered and with the use of the Citizen's Calculator (created by the central bank 31/10/2012) we were able to arouse the curiosity and interest of the majority of the students for the financial education, with the use of resources like: Blackboard, didactic books and educational material, data show. In the latter part, through price surveys in: supermarkets, physical and furniture stores in the city and neighboring cities, big store sites, motorcycle and car shops in the city and region, real estate land and houses (new and used), Banks and cooperatives of the city. The collected data were analyzed and organized into tables, graphs and models, and its culmination was presented in a seminar by the students, with visits from other classes, time teachers, pedagogical coordination and school management. For the verification of learning, a diagnostic questionnaire was applied and reapplied, where we can see the evolution of the student after experiencing this moment of interaction. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho é mais do que uma análise, é uma proposta educacional na forma de atividades de classe e extraclasse que culminam em um evento ao qual recebeu o nome de seminário de Matemática Comercial e Financeira no Ensino Fundamental II, um projeto que envolve aulas teóricas e práticas sobre a Matemática Comercial e Financeira no Ensino Fundamental II no município de Igaci (estado de Alagoas). Na primeira parte do trabalho, faz-se um levantamento bibliográfico destacando sua importância e uso no nosso cotidiano, buscamos aportes teóricos nos estudos de ANDRINI, apud VASCONCELOS (2002), NETTO (1998), LUNES, apud LIGOCKI (2015), BIGODE (2002), CENTURIÓN, apud JAKUBOVIC (2012). Na segunda parte fazemos uma breve explanação dos temas abordados e com o uso da Calculadora do Cidadão (criada pelo banco central 31/10/2012) conseguimos despertar a curiosidade e interesse da maioria dos alunos para a educação financeira, com o uso de recursos como: lousa, livros didáticos e paradidáticos, data show. Na última parte através de pesquisas de preços em: supermercados, lojas físicas de móveis e eletros da cidade e cidades vizinhas, sites de grandes lojas, lojas de motos e carros da cidade e região, imobiliária de terrenos e casas (novas e usadas), bancos e cooperativas da cidade. Os dados coletados foram analisados e organizados em tabelas, gráficos e maquetes, tendo sua culminância apresentada em um seminário pelos alunos, com visitas de outras turmas, professores do horário, coordenação pedagógica e direção escolar. Para a verificação da aprendizagem foi aplicado e reaplicado um questionário diagnóstico, onde podemos ver a evolução do alunado após vivenciar esse momento de interação.

I will attend to creation suitable model of e-marketing for e-shop with flowers in my diploma work. The aim will by join the possible instruments of online marketing in order that the company can succesfully work on the Internet. and ensure the betterposition before the competition. I will focus on e-marketing and its individua instruments. I will make some analysis of the company, by virtue of I will propose what kind of e-marketing can company use. Last but not least I will attend to the aims, which company should achieve and own potential which should valorize.