1,720,960 research outputs found
Betting, selection, and luck: A long-run analysis of repeated betting markets
No full textWe consider a repeated betting market populated by two agents who wage on a binary event according to generic betting strategies. We derive new simple criteria, based on the difference of relative entropies, to establish the relative wealth of the two agents in the long-run. Little information about agents' behavior is needed to apply the criteria: it is sufficient to know the odds traders believe fair and how much they would bet when the odds are equal to the ones the other agent believes fair. Using our criteria, we show that for a large class of betting strategies, it is generically possible that the ultimate winner is only decided by luck. As an example, we apply our conditions to the case of Constant Relative Risk Averse (CRRA) and quantal response betting
Far from the madding crowd: collective wisdom in prediction markets
No full textWe investigate market selection and bet pricing in a repeated prediction market model. We derive the conditions for long-run survival of more than one agent (the crowd) and quantify the information content of prevailing prices in the case of fractional Kelly traders with heterogeneous beliefs. It turns out that, apart some non-generic situations, prices do not converge, neither almost surely nor on average, to true probabilities, nor are they always nearer to the truth than the beliefs of all surviving agents. This implies that, in general, prediction market prices are not maximum likelihood estimators of the true probabilities. However, when more than one agent survives, the average price emerging from a prediction market approximates the true probability with lower information loss than any individual belief
Innovation, finance, and economic growth: an agent-based approach
No full textThis paper extends the endogenous growth agent-based model in Fagiolo and Dosi (Struct Change Econ Dyn 14(3):237–273, 2003) to study the finance–growth nexus. We explore industries where firms produce a homogeneous good using existing technologies, perform R&D activities to introduce new techniques, and imitate the most productive practices. Unlike the original model, we assume that both exploration and imitation require resources provided by banks, which pool agent savings and finance new projects via loans. We find that banking activity has a positive impact on growth. However, excessive financialization can hamper growth. Indeed, we find a significant and robust inverted U-shaped relation between financial depth and growth. Overall, our results stress the fundamental (and still poorly understood) role played by innovation in the finance–growth nexus
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
At the frontier of agent-based modelling: a new data driven framework for policy design toward sustainable and resilient economies
No full textIn this project we propose a novel data-driven modelling approach to evaluate economic policies, with an empirical focus on Italy and with an application to climate change mitigation policies. It builds upon the idea of combining the flexible, realistic, and disaggregated structure of agent-based models with the coherent and consistent data framework provided by the Social Accounting Matrix. To do that we need to address several challenges both on the modelling and on the data representation side. Concerning modelling, we need to face the challenge of letting the model dynamically interact with data. On the data side, we have to integrate and harmonize several data sources in a framework that can serve and guide the development of the model. We identify the key for succeeding in a continuous and bidirectional feedback between data analysis and model building. In particular, we propose a novel approach in structuring data, called Multi-Agent Social Accounting Matrix (MASAM). It consists in a new data framework where the national social accounting matrix is linked with a set of granular information on firms and households, in terms of both stocks and flows, and where financial and environmental aspects are described. This detailed data structure dynamically interacts with the model via advanced estimation, data assimilation, and validation techniques drawn from the statistical learning domain. The main test-bed for evaluating the performance of the model will be its out-of-sample forecasting accuracy of macroeconomic variables of interest. Indeed, the predictive performance of the model will be continuously assessed. In this way, we plan to promptly intervene, spotting and correcting the inconsistencies that arise. A large body of theoretical investigation will be devoted to understanding the proper level of disaggregation that the model needs to provide accurate forecasts. Once a correctly calibrated model with high predictive accuracy is available, we can perform stress-tests on the resilience of the Italian economy to various shocks, providing accurate quantitative predictions on the outcomes of different sets of policies in the short-medium run. At the same time, we will be able to provide realistic scenario analyses, simulating the behavior of the economy over longer time horizons. Given the relevance and the global concern on the topic, we apply our framework to
economic policies aimed at tackling climate change. In particular, we will investigate the consequences of fiscal and monetary policy reforms, aimed at mitigating the environmental effects of economic activity on the Italian economy. We believe that our effort toward the development of a consistent data-driven framework for agent-based modelling may constitute an important contribution to both scientific debate and policy making, especially considering the fundamental challenges the world is facing
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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