Optimal Tariffs: The Evidence

The theoretical debate over whether countries can and should set tariffs in response to the foreign export elasticities they face goes back to Edgeworth (1894). Despite the centrality of the optimal tariff argument in trade policy, there exists no evidence about whether countries actually exploit their market power in trade by setting higher tariffs on goods that are supplied inelastically. We estimate disaggregate foreign export supply elasticities and find evidence that countries that are not members of the World Trade Organization systematically set higher tariffs on goods that are supplied inelastically. The typical country in our sample sets tariffs 9 percentage points higher in goods with high market power relative to those with low market power. This large effect is of a magnitude similar to the average tariffs in the data and market power explains more of the tariff variation than a commonly used political economy variable. The result is robust to the inclusion of other determinants of tariffs and a variety of model specifications. We also find that U.S. trade restrictions that are not covered by the WTO are significantly higher in goods where the U.S. has more market power. In short, we find strong evidence that these importers have market power and use it in setting non-cooperative trade policy.

The Logic of the Method of Agent-Based Simulation in the Social Sciences: Empirical and Intentional Adequacy of Computer Programs

The classical theory of computation does not represent an adequate model of reality for simulation in the social sciences. The aim of this paper is to construct a methodological perspective that is able to conciliate the formal and empirical logic of program verification in computer science, with the interpretative and multiparadigmatic logic of the social sciences. We attempt to evaluate whether social simulation implies an additional perspective about the way one can understand the concepts of program and computation. We demonstrate that the logic of social simulation implies at least two distinct types of program verifications that reflect an epistemological distinction in the kind of knowledge one can have about programs. Computer programs seem to possess a causal capability (Fetzer, 1999) and an intentional capability that scientific theories seem not to possess. This distinction is associated with two types of program verification, which we call empirical and intentional verification. We demonstrate, by this means, that computational phenomena are also intentional phenomena, and that such is particularly manifest in agent-based social simulation. Ascertaining the credibility of results in social simulation requires a focus on the identification of a new category of knowledge we can have about computer programs. This knowledge should be considered an outcome of an experimental exercise, albeit not empirical, acquired within a context of limited consensus. The perspective of intentional computation seems to be the only one possible to reflect the multiparadigmatic character of social science in terms of agent-based computational social science. We contribute, additionally, to the clarification of several questions that are found in the methodological perspectives of the discipline, such as the computational nature, the logic of program scalability, and the multiparadigmatic character of agent-based simulation in the social sciences.Computer and Social Sciences, Agent-Based Simulation, Intentional Computation, Program Verification, Intentional Verification, Scientific Knowledge

The film industry : sequel production and release lags

The theatrical film industry can structurally be divided in three stages: production, distribution and exhibition. In each stage companies face strategic decisions that help determine the success of a given film. This thesis aims to optimize these strategic decisions on two issues: the sequel-making process, concerning producers, and the timing of release in international markets, decided by distributors. Following from these issues, two research questions are established. First, if it’s (still) worth it for a producer to make a sequel film. Second, if the time lag between releases in North America and Portugal affects a film’s revenues in the latter market. To pursue these objectives, the approach established by Basuroy & Chatterjee (2008) was followed: a Generalized Estimating Equations (GEE) method, under a Gaussian family, with an identity link and exchangeable correlation structure. For the producer’s problem, data was obtained for 208 films released in 2011 in North America. The results show that sequel films consistently outperform non-sequels at the box office. Furthermore, this effect is moderated by longer time gaps between parent and target and producers should expect faster decaying weekly revenues from sequels. For the distributor’s problem, Portuguese data consists of 139 of those films covered in the producer’s problem, which, due to release lags, were released in Portugal between 2009 and 2013. The results show that longer release lags have a significant and negative effect on revenues and that this effect is largely concentrated in the first few weeks of a films’ release

Multiple Sensor Interface by the same hardware to USB and serial connection

The Multiple Sensor Interface is a simple sensor interface that works with USB, RS485 and GPIO. It allows one to make measurements using a variety of sensors based on the change of inductance, resistance, capacitance, and frequency using the same connector and same electronic interface circuit between the sensor and the microcontroller. The same device also provides some additional connectors for small voltage measurement. Any sensors used for the measurement of distinct phenomena can be used if the sensor output is based on inductance, resistance, capacitance or frequency within the measurement range of the device, obtaining a variable precision depending on the used sensor. The device presented is not meant for precise or accurate measurements. It is meant to be a reusable hardware that can be adapted/configured to a varied number of distinct situations, providing, to the user, more freedom in sensor selection as well as more options for device/system maintenance or reuse.Comment: 15 pages, 28 figures, personal project blog: https://multiple-sensor-interface.blogspot.co