Searching for the Kuhnian moment : the Black-Scholes-Merton formula and the evolution of modern finance theory

The Black-Scholes-Merton formula has been put to widespread use by options traders because it provides a means of calculating the theoretically 'correct' price of stock options. Traders can therefore see whether the market price of stock options undervalues or overvalues them compared with their hypothetical Black-Scholes-Merton price, before choosing to buy or sell options accordingly. As a consequence of this close relationship between options pricing theory and options pricing practice, a strong performativity loop was activated, whereby market prices quickly converged on the hypothetical Black-Scholes-Merton prices following the dissemination of the formula. The theory has therefore had significant real-world effects, but how should we characterize the initial instinct to derive the theory from a philosophy of science perspective? The two books under review suggest that a Kuhnian reading of the advancement of scientific knowledge might well be the most appropriate. But, on closer inspection, it becomes clear that the publication of the Black-Scholes-Merton formula should not be seen as a Kuhnian moment with paradigm-shaping attributes. It is shown that, at most, the formula acts as an important exemplar which, via its use in the training of options pricing theorists and options pricing practitioners, reinforces the entrenchment of finance theory within the orthodox economics worldview

Putnam's theory of natural kinds and their names is not the same as kripke's

  Philosophers have been referring to the “Kripke–Putnam” theory of naturalkind terms for over 30 years. Although there is one common starting point, the two philosophers began with different motivations and presuppositions, and developed in different ways. Putnam’s publications on the topic evolved over the decades, certainly clarifying and probably modifying his analysis, while Kripke published nothing after 1980. The result is two very different theories about natural kinds and their names. Both accept that the meaning of a naturalkindterm is not given by a description or defining properties, but is specified byits referents. From then on, Putnam rejected even the label, causal theory of reference, preferring to say historical, or collective. He called his own approachindexical. His account of substance identity stops short a number of objections that were later raised, such as what is called the qua problem. He came to reject the thought that water is necessarily H2O, and to denounce the ideaof metaphysical necessity that goes beyond physical necessity. Essences never had a role in his analysis; there is no sense in which he was an essentialist. He thought of hidden structures as the usual determinant of natural kinds, but always insisted that what counts as a natural kind is relative to interests.“Natural kind” itself is itself an importantly theoretical concept, he argued. The paper also notes that Putnam says a great deal about what natural kinds are, while Kripke did not. Moreover, a theory about names of natural kinds is to some extent independent of a theory of natural kinds themselves, to the extent that one can accept the one and reject the other, even when both are advanced by the same philosopher

As coisas dependem mais do seu nome do que daquilo que são

This article examines a particular relationship between names and things. Initially examines the tradition that treats this issue in the history of philosophy especially those who criticize the universalist that tries to put human beings into a nature. Finally tries to demonstrate the intimate relationship of dependency that there may be among the names and the things that captures the names and the influence of the names on things that we can draw as dynamic nominalism. Keywords: dynamic nominalism, human nature, language, reality.Este artigo analisa uma particular relação entre os nomes e as coisas. Inicialmente percorre a tradição que trata esta problemática na historia da fi losofi a sobretudo os que criticam os universalistas no sentido de querer colocar os seres humanos dentro de uma natureza. Finalmente tentará demonstrar a intima relação de dependência que pode haver entre os nomes e as coisas que recebem esses nomes e a influência dos nomes nas coisas numa dialética que podemos chamar de nominalismo dinâmico. Palavras-chave: nominalismo dinâmico, natureza humana, linguagem, realidade

IR Spectrometer Using 90-degree Off-axis Parabolic Mirrors

A gated spectrometer has been designed for real-time, pulsed infrared (IR) studies at the National Synchrotron Light ource at the Brookhaven National Laboratory. A pair of 90-degree, off-axis parabolic mirrors are used to relay the light from an entrance slit to an output IR recording camera. With an initial wavelength range of 1500–4500 nm required, gratings could not be used in the spectrometer because grating orders would overlap. A magnesium oxide prism, placed between these parabolic mirrors, serves as the dispersion element. The spectrometer is doubly telecentric. With proper choice of the air spacing between the prism and the second parabolic mirror, any spectral region of interest within the InSb camera array’s sensitivity region can be recorded. The wavelengths leaving the second parabolic mirror are collimated, thereby relaxing the camera positioning tolerance. To set up the instrument, two different wavelength (visible) lasers are introduced at the entrance slit and made collinear with the optical axis via flip mirrors. After dispersion by the prism, these two laser beams are directed to tick marks located on the outside housing of the gated IR camera. This provides first-order wavelength calibration for the instrument. Light that is reflected off the front prism face is coupled into a high-speed detector to verify steady radiance during the gated spectral imaging. Alignment features include tick marks on the prism and parabolic mirrors. This instrument was designed to complement singlepoint pyrometry, which provides continuous time histories of a small collection of spots from shock-heated targets

A Mouse Model of Harlequin Ichthyosis Delineates a Key Role for Abca12 in Lipid Homeostasis

Harlequin Ichthyosis (HI) is a severe and often lethal hyperkeratotic skin disease caused by mutations in the ABCA12 transport protein. In keratinocytes, ABCA12 is thought to regulate the transfer of lipids into small intracellular trafficking vesicles known as lamellar bodies. However, the nature and scope of this regulation remains unclear. As part of an original recessive mouse ENU mutagenesis screen, we have identified and characterised an animal model of HI and showed that it displays many of the hallmarks of the disease including hyperkeratosis, loss of barrier function, and defects in lipid homeostasis. We have used this model to follow disease progression in utero and present evidence that loss of Abca12 function leads to premature differentiation of basal keratinocytes. A comprehensive analysis of lipid levels in mutant epidermis demonstrated profound defects in lipid homeostasis, illustrating for the first time the extent to which Abca12 plays a pivotal role in maintaining lipid balance in the skin. To further investigate the scope of Abca12's activity, we have utilised cells from the mutant mouse to ascribe direct transport functions to the protein and, in doing so, we demonstrate activities independent of its role in lamellar body function. These cells have severely impaired lipid efflux leading to intracellular accumulation of neutral lipids. Furthermore, we identify Abca12 as a mediator of Abca1-regulated cellular cholesterol efflux, a finding that may have significant implications for other diseases of lipid metabolism and homeostasis, including atherosclerosis

Experimental Practices in Economics: Performativity and the Creation of Phenomena

This contribution provides a brief overview and discussion of the role of experiments in economics. It is argued that economic experiments have convinced economists and the public of the existence of phenomena that have been outside the scope of economics. The success of these experiments is partly due to the performative nature of experiments. To develop this argument, examples of experiments are provided, and two different sets of criticisms of experiments are discussed. The paper concludes with a discussion of which questions economists should address and how experiments can be used to study policy-relevant questions.Der Beitrag beschäftigt sich mit der Rolle von Experimenten in der Ökonomie. Es wird argumentiert, dass Experimente dazu in der Lage sind, sowohl Ökonomen als auch eine breitere Öffentlichkeit davon zu überzeugen, dass bestimmte Phänomene existieren, die vorher nicht als relevant für die Ökonomie angesehen oder gar nicht wahrgenommen wurden. Diese Wirkung von Experimenten beruht zu einem wichtigen Teil auf ihrer Performativität. Um dieses Argument zu entwickeln, werden Beispiele für Experimente gegeben, verschiedene Kritikpunkte an Experimenten diskutiert sowie die Frage aufgeworfen, was die Grenzen der Ökonomie sind und wie Experimente zur Beantwortung wirtschaftspolitischer Fragen eingesetzt werden können

The politics of evidence: methodologies for understanding the global land rush

Since the most recent ‘land rush’ precipitated by the convergent ‘crises’ of fuel, feed and food in 2007-08, the debate on the consequences of land investments has been massively heightened, with widespread media coverage, policy commentary and civil society engagement. The ‘land rush’ of recent years has been accompanied by a ‘literature rush’, with a fast-growing body of reports, articles, tables and books with varied purposes, metrics and methods. ‘Land grabbing’ is now a hot political topic around the world, discussed amongst the highest circles. This is why getting the facts right is really important, and having effective methodologies is crucial. Several global initiatives have set out to aggregate information on land deals, and to describe their scale, character and distribution. All have contributed to building a better picture of the phenomenon, but all have struggled with methodology. This JPS Forum identifies a profound uncertainty about what it is that is being counted, questions methods used to collate and aggregate ‘land grabs’, and calls for a second phase of land grab research which abandons the aim of deriving total numbers of hectares in favour of more specific, grounded and transparent methods.ESR