Co-movement between two processes with local persistence

This paper introduces a residual based test where the null hypothesis of c:&InOvement between two processes with local persistenc~ can be tested, even under the presence of an endogenous regressor. It, therefore, fills in an existing lacuna in econometrics, in which longrun relationships can also be tested if the dependent and independent variables do not have a unit root, but do exhibit local persistence.

Exploratory semiparametric analysis of two-dimensional diffusions in finance

We examine bivariate extensions of Aït-Sahalia’s approach to the estimation of univariate diffusions. Our message is that extending his idea to a bivariate setting is not straightforward. In higher dimensions, as opposed to the univariate case, the elements of the Itô and Fokker-Planck representations do not coincide; and, even imposing sensible assumptions on the marginal drifts and volatilities is not sufficient to obtain direct generalisations. We develop exploratory estimation and testing procedures, by parametrizing the drifts of both component processes and setting restrictions on the terms of either the Itô or the Fokker-Planck covariance matrices. This may lead to highly nonlinear ordinary differential equations, where the definition of boundary conditions is crucial. For the methods developed, the Fokker-Planck representation seems more tractable than the Itô’s. Questions for further research include the design of regularity conditions on the time series dependence in the data, the kernels actually used and the bandwidths, to obtain asymptotic properties for the estimators proposed. A particular case seems promising: “causal bivariate models” in which only one of the diffusions contributes to the volatility of the other. Hedging strategies which estimate separately the univariate diffusions at stake may thus be improved.

Nonparametric entropy-based tests of independence between stochastic processes

This paper develops nonparametric tests of independence between two stationary stochastic processes. The testing strategy boils down to gauging the closeness between the joint and the product of the marginal stationary densities. For that purpose, I take advantage of a generalized entropic measure so as to build a class of nonparametric tests of independence. Asymptotic normality and local power are derived using the functional delta method for kernels, whereas finite sample properties are investigated through Monte Carlo simulations.

The family role on the internationalization process of family businesses: a two-case study

Essa dissertação procura identificar o papel da família no processo de internacionalização de dois negócios familiares: JBS, a maior empresa de proteína animal do mundo e Cutrale um dos líderes mundiais no mercado de suco de laranja. Empresas familiares possuem características que são intrínsecas a esse tipo de empresa. Muitos dos motivos de se internacionalizar ou mesmo o modo como eles se internacionalizam podem ser extremamente característicos. Assim, através de uma pesquisa qualitativa, os dois estudos de caso foram analisados baseados em teorias de internacionalização de empresas familiares. Porém, nessas companhias estudadas, a família não desempenhou um papel relevante no processo de internacionalização das mesmas. Com esses resultados, questões surgiram, como por exemplo, se o tamanho ou segmento da empresa tiveram um impacto na importância do papel que a família possui no processo de internacionalização. Essas questões não eram o foco do estudo porém fornecem muitos subsídios para uma próxima pesquisa.

Duality with time-changed Lévy processes

In this paper we study the pricing problem of derivatives written in terms of a two dimensional time{changed L¶evy processes. Then, we examine an existing relation between prices of put and call options, of both the European and the American type. This relation is called put{call duality. It includes as a particular case, the relation known as put{call symmetry. Necessary and su±cient conditions for put{call symmetry to hold are shown, in terms of the triplet of local charac- teristic of the Time{changed L¶evy process. In this way we extend the results obtained in Fajardo and Mordecki (2004) to the case of time{changed Lévy processes.

Strategic adoption in a two-sided market : a study of college applications in Brazil

This paper measures the importance of indirect network effects in the adoption by colleges and students of ENEM, a standardized exam for high-school students in Brazil that can be used in college application processes. We estimate network effects and find that they are economically significant. Students are more likely to take ENEM the larger the number of colleges adopting it. Similarly, colleges are more likely to adopt it the larger the number of students taking the exam. Moreover, we find evidence that colleges play strategically and that heterogeneity determines their decisions. A college is less likely to adopt ENEM the larger the number of competitors adopting it. Colleges’ characteristics such as ownership and organization affect adoption decisions. In a counterfactual exercise we compare colleges’ adoption decisions under competition and under joint colleges’ payoffs maximization. Adoption rates are significantly reduced when colleges internalize the competitive effect, i.e., the effect of their decisions on other colleges’ payoffs. On the other hand, they increase when indirect network effects - the effect of students’ response to their decisions on other colleges’ payoffs - are also internalized. Competitive adoption rates are found to exceed joint optimum rates by a small difference. These results suggest that, without considering students’ welfare, adoption rates are excessive, but close to the joint optimum.