In this paper, we consider a nonlinear model based on neural networks as well as linear models to forecast the daily volatility of the S&P 500 and FTSE 100 futures. As a proxy for daily volatility, we consider a consistent and unbiased estimator of the integrated volatility that is computed from high-frequency intraday returns. We also consider a simple algorithm based on bagging (bootstrap aggregation) in order to specify the models analysed in this paper.

Whether campaign advertising influences election outcomes is an open question; a paradox given the amount spent on campaigning in general and TV advertising in particular. We argue that such “absence of documentation” is due to the focus of the empirical literature on the U.S., where the allocation of campaign spending and advertising is decentralized. We explore a quasi-natural experiment that enables us to mitigate the omitted variables and reverse causality problems caused by decentralized allocation. In Brazil, gubernatorial elections work in a two-round system. In the first round, candidates' TV time shares are determined by their coalitions' share of seats in the National Parliament. In the second round, TV time is split equally between the first-round winner and runner-up. Using differences between rounds as a source of variation, we find a large causal effect of TV advertising on election outcomes.

We study the purchasing power parity (PPP) puzzle in a multisector, two-country, sticky-price model. Sectors differ in the extent of price stickiness, leading to heterogeneous sectoral real exchange rate dynamics. Deviations from PPP are more volatile and persistent than in an otherwise identical one-sector world economy with the same average frequency of price changes. Under the empirical distribution of price stickiness of the US economy, the model produces PPP deviations with a half-life of 39 months. We provide a structural interpretation of the approaches found in the empirical literature on aggregation and PPP, and reconcile its apparently conflicting findings.

O nível de educação dos pais está bastante associado ao desempenho dos filhos no mercado de trabalho no Brasil. Com isso, a estrutura educacional da família pode desempenhar um papel importante na determinação da elevada disparidade de rendimentos observada. Utilizando dados do suplemento sobre mobilidade social da PNAD (Pesquisa Nacional por Amostra de Domicílios) de 1996, este artigo analisa a relação entre a distribuição de rendimentos do trabalho no Brasil e a escolaridade dos pais dos trabalhadores. De acordo com os resultados, a estrutura educacional da família, através tanto da sua influência sobre o nível educacional dos trabalhadores como, em menor escala, sobre os retornos para a escolaridade, parece um importante determinante da desigualdade nos rendimentos do trabalho

This paper considers the problem faced by two regulators in providing incentives to a common (privately informed) regulated firm under various degrees of coordination. In the model, the firm exerts effort toward cost reduction and self-dealing, and incentives can be input-based (monitoring) and output-based (demanded cost targets). Full coordination between the regulators leads to the second best allocation. A setting in which the regulators do not fully coordinate leads to (i) higher overall monitoring (more aggressive input-based incentives) and (ii) higher demanded cost targets (i.e., more lenience in terms of output-based incentives). As a consequence of (i,0), in all possible equilibria, the effort toward cost reduction will be smaller when the agent reports to two regulators who do not coordinate. (i) and (ii) imply that the impact on the effort toward self-dealing activities is ambiguous. In our leading example, self-dealing will be larger if the regulators coordinate on monitoring levels but smaller if they choose monitoring levels independently.

One dimension of competition among stock exchanges is the quality of products they have to offer. In order to attract listings and trading volume, exchanges can affect the quality of their listed firms by altering their standards for firm disclosure and governance. We identify a competition with respect to delisting standards between Korea's two stock exchanges and show that it complies with the three components of a regulatory race to the top: external trigger, mobility among diverse regimes and meaningful changes that converge to similar rules. The race between the two Korean exchanges ended with stricter rules and better protected minority shareholders. The race also ended, however, with neither exchange gaining market share with respect to trading volume or new listings. Korea's experience, therefore, suggests a reason why these races are rare. In the absence of an external trigger, exchanges will be reluctant to enter a race if they think it will result in rule convergence and no winner

In this paper, we introduce a linearity test for fuzzy rule-based models in the framework of time series modeling. To do so, we explore a family of statistical models, the regime switching autoregressive models, and the relations that link them to the fuzzy rule-based models. From these relations, we derive a Lagrange multiplier linearity test and some properties of the maximum likelihood estimator needed for it. Finally, an empirical study of the goodness of the test is presented

Este trabalho tem como objetivo investigar os determinantes do diferencial de rendimentos público-privado para diferentes níveis de escolaridade dos trabalhadores no Brasil. Primeiramente, utilizando o rendimento do trabalho principal como variável de interesse, é estimado um hiato de rendimentos bastante favorável ao setor público para trabalhadores com baixa escolaridade. Já para trabalhadores mais qualificados, o hiato tende a desaparecer ou mesmo a tornar-se favorável ao setor privado. Adicionalmente, de maneira a considerar os diferentes regimes de aposentadoria vigentes no país, é definida a variável Valor Presente do Contrato de Trabalho (VPCT) como medida dos rendimentos dos indivíduos ao longo da vida. Diferentemente do resultado encontrado utilizando o rendimento do trabalho, é verificado que o diferencial do VPCT é favorável ao setor público mesmo para trabalhadores com elevados níveis de escolaridade