671 research outputs found

    A Comment on Anna Carabelli’s «Keynes’s Uncertainty as a Tragic Rational Dilemma»

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    The paper comments on Anna Carabelli's view on Keynes's probability theor

    A Comment on Donald Gillies’s «Difficulties in the Logical Interpretation of Probability»

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    The paper comments on Donald Gillies's views of Keynes's probability theor

    On measurable uncertainty and the fight for taking uncertainty seriously in economics

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    This paper discusses the engagement of economists with the issue of the measurability of uncertainty. Since Knight’s seminal distinction between risk, intended as measurable uncertainty, and unmeasurable uncertainty, the question has been to what extent the extension of the theory of choice from certainty to risk through von Neumann and Morgenstern’s expected utility hypothesis would allow dealing with uncertain events. The paper develops from a study of the rationale underlying the theories of those authors who objected to the mainstream view that the axiomatic approach developed in the early 1950s, mainly through Leonard Savage’s generalization of expected utility, makes it, indeed, possible to reduce uncertainty to risk. After a summary of the meaning attributed by authors such as Knight, Keynes, Shackle and Ellsberg to the contention that uncertainty is irreducible to risk and unmeasurable, the paper aims to investigate why this view did not emerge as a significant alternative to the mainstream up until recently. A main reason, at times alluded to but never openly discussed in the literature, is shown to be the close link between Savage and the group of decision theorists at the Cowles Commission for Research in Economics under the directorship of Jacob Marschak and Tjalling Koopmans. Archival evidence suggests that arguing that a theory of decision under uncertainty could be developed on the basis of “axioms that seem unobjectionable,” as Koopmans put it, was indeed an integral part of the attempt undertook at Cowles to move forward in economic theory by prioritizing scientific rigour in the form of mathematical models engaging with new mathematical tools

    Keynes’s Treatise on Probability at 100: A Symposium. Introduction

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    This paper introduces the symposium reproducing the four papers presented at the STOREP 2021 Annual Conference, in the virtual session especially dedicated to celebrate the centennial anniversary of the Treatise. The papers testify well to the diversity of views about the significance of Keynes’s volume for both the probability theory and the main theme in Keynes’s economics, namely, the pervasiveness of uncertainty in the economy and its substantial neglect by «classical» economists

    Keyne's Treatise on Probability at 100 years: its most enduring message

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    On the occasion of the assessment of the enduring influence of Keynes’s Treatise on Probability at 100 years, this paper focuses on its relevance for decision theory. The paper places emphasis on Keynes’s introduction of the epistemic notion of probabilities that often are non-numerical, as a theoretical object intended to replace frequency probabilities. The paper argues that, as non-numerical probabilities make it possible to deal with uncertainty as if individuals were endowed with interval-valued probabilities, Keynes’s 1921 critique of contemporary frequency probability theory turns out to be relevant also with regard to the yet to be established subjective probability theory. Although non-numerical probabilities were used by Keynes to criticize the contemporary application of probability to conduct, it must be acknowledged that, still today, they may constitute an appropriate tool for decision-making when confronting uncertainty, as he hinted at in his late 1930s correspondence with Hugh Townshend

    De Finetti on the insurance of risks and uncertainties

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    In the insurance literature, it is often argued that private markets can provide insurance against ‘risks’ but not against ‘uncertainties’ in the sense of Knight ([1921]) or Keynes ([1921]). This claim is at odds with the standard economic model of risk exchange which, in assuming that decision-makers are always guided by point-valued subjective probabilities, predicts that all uncertainties can, in theory, be insured. Supporters of the standard model argue that the insuring of highly idiosyncratic risks by Lloyd's of London proves that this is so even in practice. The purpose of this article is to show that Bruno de Finetti, famous as one of the three founding fathers of the subjective approach to probability assumed by the standard model, actually made a theoretical case for uncertainty within the subjectivist approach. We draw on empirical evidence from the practice of underwriters to show how this case may help explain the reluctance of insurers to cover highly uncertain contingencies

    De Finetti on uncertainty

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    The well-known Knightian distinction between quantifiable risk and unquantifiable uncertainty is at odds with the dominant subjectivist conception of probability associated with de Finetti, Ramsey and Savage. Risk and uncertainty are rendered indistinguishable on the subjectivist approach insofar as an individual’s subjective estimate of the probability of any event can be elicited from the odds at which she would be prepared to bet for or against that event. The risk/uncertainty distinction has however never quite gone away and is currently under renewed theoretical scrutiny. The purpose of this article is to show that de Finetti’s understanding of the distinction is more nuanced than is usually admitted. Relying on usually overlooked excerpts of de Finetti’s works commenting on Keynes, Knight and interval valued probabilities, we argue that de Finetti suggested a relevant theoretical case for uncertainty to hold even when individuals are endowed with subjective probabilities. Indeed, de Finetti admitted that the distinction between risk and uncertainty is relevant when different individuals sensibly disagree about the probability of the occurrence of an event. We conclude that the received interpretation of de Finetti’s understanding of subjective probability needs to be qualified on this front

    Foundations in Wisconsin: A Directory [34th ed. 2015]

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    The 2015 release of Foundations in Wisconsin marks the 34th production of the print directory and the 15th year of the online version. The directory is designed as a research tool for grantseekers interested in locating information on private, corporate, and community foundations registered in Wisconsin. Each entry in this new edition has been updated or reviewed to provide the most current information available. Most of the data was drawn from IRS 990-PF tax returns filed by the foundations. Additional information was obtained from surveys, foundation websites, annual reports, and newsletters. Wisconsin foundations have shown significant growth in two key areas. Grant and asset totals have risen to to their highest recorded levels. Total grants increased by 5% to 579millionandassetsby17579 million and assets by 17% to 9.5 billion. Additionally, 58 new foundations have been identified this edition. (See page 271 for the complete list.)https://epublications.marquette.edu/lib_fiw/1013/thumbnail.jp

    Mild behavioral impairment in Parkinson's disease: Data from the Parkinson's disease cognitive impairment study (PACOS)

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    Neuropsychiatric symptoms (NPS) have been frequently described in Parkinson's disease (PD), even in the earliest stages of the disease. Recently the construct of mild behavioral impairment (MBI) has been proposed as an at-risk state for incident cognitive decline and dementia. The aim of the present study is to evaluate the prevalence and associated factors of MBI in PD. Cross-sectional data from 429 consecutive PD patients enrolled in the PArkinson's disease COgnitive impairment Study (PACOS) were included in the study. All subjects underwent neuropsychological assessment, according to the MDS Level II criteria. NPS were evaluated with the Neuropsychiatric Inventory. Multivariate logistic regression models were used to evaluate clinical and behavioral characteristics, which are associated with PD-MBI. The latter was ascertained in 361 (84.1%) subjects of whom 155 (36.1%) were newly diagnosed patients (disease duration ≄1 year) and 206 (48.0%) had a disease duration <1 year. Furthermore, 68 (15.9%) out of 429 subjects were PDw (without MBI). Across the MBI domains, Impulse Dyscontrol was significantly more prevalent among PD-MBI with disease duration <1 year than newly diagnosed patients. The frequency of Social Inappropriateness and Abnormal Perception significantly increased throughout the entire PD-MBI sample with increasing Hoehn andYahr (H&Y) stages. PD-MBI in newly diagnosed PDwas significantly associated with H&Y stage (OR 2.35, 95% CI 1.05-5.24) and marginally with antidepressant drug use (OR 2.94, 95% CI 0.91-9.47), while in patients with a disease duration >1 year was associated with UPDRS-ME (OR 3.37, 95% CI 1.41-8.00). The overall MBI frequency in the PACOS sample was 84% and 36% among newly diagnosed patients. The presence of MBI mainly related to motor impairment and disability

    Foundations in Wisconsin: A Directory [35th ed. 2016]

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    The 2016 release of Foundations in Wisconsin marks the 35th edition of the print directory and the 16th edition of the online version. The directory is designed as a research tool for grantseekers interested in locating information on private, corporate, and community foundations registered in Wisconsin. Each entry in this new edition has been updated or reviewed to provide the most current information available. Most of the data was drawn from IRS 990-PF tax returns filed by the foundations. Additional information was obtained from surveys, foundation websites, and annual reports. This edition paints a very positive picture of financial growth for Wisconsin foundations. Both grant and asset totals have risen to all-time highs. Of particular note, total grants broke the 600millionbarrier,increasingby8600 million barrier, increasing by 8% to 623 million. Additionally, 58 new foundations have been identified this year. (See page 269 for the complete list.) The following table illustrates the 10-year financial pattern as documented in Foundations in Wisconsin.https://epublications.marquette.edu/lib_fiw/1014/thumbnail.jp
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