Probabilidades imprecisas: intervalar, fuzzy e fuzzy intuicionista

The idea of considering imprecision in probabilities is old, beginning with the Booles George work, who in 1854 wanted to reconcile the classical logic, which allows the modeling of complete ignorance, with probabilities. In 1921, John Maynard Keynes in his book made explicit use of intervals to represent the imprecision in probabilities. But only from the work ofWalley in 1991 that were established principles that should be respected by a probability theory that deals with inaccuracies. With the emergence of the theory of fuzzy sets by Lotfi Zadeh in 1965, there is another way of dealing with uncertainty and imprecision of concepts. Quickly, they began to propose several ways to consider the ideas of Zadeh in probabilities, to deal with inaccuracies, either in the events associated with the probabilities or in the values of probabilities. In particular, James Buckley, from 2003 begins to develop a probability theory in which the fuzzy values of the probabilities are fuzzy numbers. This fuzzy probability, follows analogous principles to Walley imprecise probabilities. On the other hand, the uses of real numbers between 0 and 1 as truth degrees, as originally proposed by Zadeh, has the drawback to use very precise values for dealing with uncertainties (as one can distinguish a fairly element satisfies a property with a 0.423 level of something that meets with grade 0.424?). This motivated the development of several extensions of fuzzy set theory which includes some kind of inaccuracy. This work consider the Krassimir Atanassov extension proposed in 1983, which add an extra degree of uncertainty to model the moment of hesitation to assign the membership degree, and therefore a value indicate the degree to which the object belongs to the set while the other, the degree to which it not belongs to the set. In the Zadeh fuzzy set theory, this non membership degree is, by default, the complement of the membership degree. Thus, in this approach the non-membership degree is somehow independent of the membership degree, and this difference between the non-membership degree and the complement of the membership degree reveals the hesitation at the moment to assign a membership degree. This new extension today is called of Atanassov s intuitionistic fuzzy sets theory. It is worth noting that the term intuitionistic here has no relation to the term intuitionistic as known in the context of intuitionistic logic. In this work, will be developed two proposals for interval probability: the restricted interval probability and the unrestricted interval probability, are also introduced two notions of fuzzy probability: the constrained fuzzy probability and the unconstrained fuzzy probability and will eventually be introduced two notions of intuitionistic fuzzy probability: the restricted intuitionistic fuzzy probability and the unrestricted intuitionistic fuzzy probability

Clássicos versus Keynes: a abordagem formal de David Champernowne

Este texto tem por objetivo ressaltar um aspecto que não tem sido tratado com a devida profundidade na literatura que estuda a formalização da Teoria Geral do Emprego, dos Juros e da Moeda de John Maynard Keynes (1936). Mais precisamente, o texto destaca a estratégia de formalização adotada por David G. Champernowne em seu artigo intitulado Unemployment, Basic and Monetary: the classical analysis and the keynesian, publicado em 1935-36 na Review of Economic Studies. Chamamos a atenção para o fato dele distinguir a teoria clássica da teoria de Keynes não apenas pelos pressupostos adotados por cada teoria, mas principalmente pela construção de subsistemas a partir de um sistema geral, com características recursivas (relações de causalidade) distintas. As explicações em prosa, a descrição algébrica das funções comportamentais e condições de equilíbrio e a ilustração por meio de diagramas, além da escolha de conjuntos específicos de variáveis para representar cada uma das teorias e suas diferentes versões são aspectos deste artigo de Champernowne que merecem uma análise mais minuciosa.

Política fiscal e reestruturação da dívida pública no Brasil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Die wirtschaftlichen Folgen des Friedensvertrages

von John Maynard Keynes

Free recombination within Helicobacter pylori

Sequences of three gene fragments (flaA, flaB, and vacA) from Helicobacter pylori strains isolated from patients in Germany, Canada, and South Africa were analyzed for diversity and for linkage equilibrium by using the Homoplasy Test and compatibility matrices. Horizontal genetic exchange in H. pylori is so frequent that different loci and polymorphisms within each locus are all at linkage equilibrium. These results indicate that H. pylori is panmictic. Comparisons with sequences from Escherichia coli, Neisseria meningitidis, and Drosophila melanogaster showed that recombination in H. pylori was much more frequent than in other species. In contrast, when multiple family members infected with H. pylori were investigated, some strains were indistinguishable at all three loci. Thus, H. pylori is clonal over short time periods after natural transmission.

Keynes at Harvard; economic deception as a political credo.

Mode of access: Internet.

Die wirtschaftlichen folgen des Friedensvertrages,

Mode of access: Internet.

A treatise on probability,

Mode of access: Internet.

ケインズ貨幣論

Mode of access: Internet.

The economic consequences of the peace,

Mode of access: Internet.

The authority of complexity

The assertion about the unique 'complexity' or the peculiarly intricate character of social phenomena has, at least within sociology, a long, venerable and virtually uncontested tradition. At the turn of the last century, classical social theorists, for example, Georg Simmel and Emile Durkheim, made prominent and repeated reference to this attribute of the subject matter of sociology and the degree to which it complicates, even inhibits the development and application of social scientific knowledge. Our paper explores the origins, the basis and the consequences of this assertion and asks in particular whether the classic complexity assertion still deserves to be invoked in analyses that ask about the production and the utilization of social scientific knowledge in modern society. We present John Maynard Keynes' economic theory and its practical applications as an illustration. We conclude that the practical value of social scientific knowledge is not dependent on a faithful, in the sense of complete, representation of social reality. Instead, social scientific knowledge that wants to optimize its practicality has to attend and attach itself to elements of social situations that can be altered or are actionable.

The unique complexity of social phenomena and the uses of social science knowledge

The assertion about the peculiarly intricate and complex character of social phenomena has, in much of social discourse, a virtually uncontested tradition. A significant part of the premise about the complexity of social phenomena is the conviction that it complicates, perhaps even inhibits the development and application of social scientific knowledge. Our paper explores the origins, the basis and the consequences of this assertion and asks in particular whether the classic complexity assertion still deserves to be invoked in analyses that ask about the production and the utilization of social scientific knowledge in modern society. We refer to one of the most prominent and politically influential social scientific theories, John Maynard Keynes' economic theory as an illustration. We conclude that, the practical value of social scientific knowledge is not necessarily dependent on a faithful, in the sense of complete, representation of (complex) social reality. Practical knowledge is context sensitive if not project bound. Social scientific knowledge that wants to optimize its practicality has to attend and attach itself to elements of practical social situations that can be altered or are actionable by relevant actors. This chapter represents an effort to re-examine the relation between social reality, social scientific knowledge and its practical application. There is a widely accepted view about the potential social utility of social scientific knowledge that invokes the peculiar complexity of social reality as an impediment to good theoretical comprehension and hence to its applicability.

Die Macht der Erkenntnis

John Maynard Keynes als »Retter des Kapitalismus« hat die westlichen Demokratien grundlegend verändert und die Grundlagen für eine neue und erneut aktuelle Wirtschaftspolitik geschaffen. Im Fall der »Rassenhygiene« haben Wissenschaftler als Vordenker der Vernichtung kulturelle und politische Ressourcen genutzt, um ihre Wissensansprüche durchzusetzen – mit fatalen Folgen. Der Klimawandel schließlich ist ein von Wissenschaftlern, Politikern und Experten intensiv diskutiertes Thema, gleichwohl haben die diesbezüglichen Erkenntnisse einen überraschend geringen Einfluß auf die praktische Politik. Anhand dieser drei Beispiele untersucht das Buch das prekäre Verhältnis von Wissen und politischer Macht.

El multilateralismo como intervencionismo. Estados Unidos y la Sociedad de Naciones en América Latina (1930-1946)

Este artículo analiza una dinámica de intervenciones de Estados Unidos en América Latina que no ha atraído suficientemente la atención de los historiadores. En los años treinta y cuarenta, cuando Europa se hundía en una nueva confrontación bélica, ciertos sectores del gobierno y del mundo empresarial norteamericano intentaron articular una nueva relación con los países del continente basada en una propuesta de multilateralismo que se había configurado dentro de la Sociedad de Naciones (SN). Estos estadounidenses intentaron establecer una dinámica de relaciones triangulares con los gobiernos latinoamericanos y los organismos técnicos de la SN. Gracias a ello, como se mostrará en este artículo para el caso del funcionamiento del Comité Fiscal de la Sociedad de Naciones, los latinoamericanos fueron capaces de influir en el tipo de políticas que debían emanar de esta relación triangular. La importancia de esta historia no es menor. La relación triangular entre Estados Unidos, América Latina y la SN sirvió de base para la reconstrucción de la gobernanza global liderada por los Estados Unidos tras la guerra.

Keynes’s "Treatise on Money" and the role of the State

Este artículo hace una reconstrucción crítica de la visión de Keynes sobre la relación entre gasto público, tipo de interés, salarios y desempleo, tal y como se formula en su Tratado sobre el Dinero. El trabajo defiende que el enfoque de Keynes lleva a propuestas de política económica que enfatizan la necesidad de intervención estatal directa en la provisión de bienes y servicios. Esta conclusión se deriva de una interpretación circuitista de su obra.