Indeterminacy In Order Research Articles

Identification of Structural VAR Models via Independent Component Analysis: A Performance Evaluation Study

Independent Component Analysis (ICA) is a statistical method that linearly transforms a random vector. Under the assumption that the observed data are mixtures of non-Gaussian and independent processes, ICA is able to recover the underlying components, but with a scale and order indeterminacy. Its application to structural vector autoregressive (SVAR) models allows the researcher to recover the impact of independent structural shocks on the observed series from estimated residuals. We analyze different ICA estimators, recently proposed within the field of SVAR analysis, and compare their performance in recovering structural coefficients. Moreover, we assess the size distortions of the estimators in hypothesis testing. We conduct our analysis by focusing on non-Gaussian distributional scenarios that get gradually close to the Gaussian case. The latter is the case where ICA methods fail to recover the independent components. Although the ICA estimators that we analyze show similar pattern of performance, two of them — the fastICA algorithm and the pseudo-maximum likelihood estimator — tend to perform relatively better in terms of variability, stability across sub- and super-Gaussian settings, and size distortion. We finally present an empirical illustration using US data to identify the effects of government spending and tax cuts on economic activity, thus providing an example where ICA techniques can be used for hypothesis testing.

Identification of Structural VAR Models Via Independent Component Analysis: A Performance Evaluation Study

Independent Component Analysis (ICA) is a statistical method that transforms a set of random variables in least dependent linear combinations. Under the assumption that the observed data are mixtures of non-Gaussian and independent processes, ICA is able to recover the underlying components, but a scale and order indeterminacy. Its application to structural vector autoregressive (SVAR) models allows the researcher to recover the impact of independent structural shocks on the observed series from estimated residuals. We analyze different ICA estimators, recently proposed within the field of SVAR identification, and compare their performance in recovering structural coefficients. Moreover, after suggesting an algorithm that solve the ICA indeterminacy problem, we assess the size distortions of the estimators in hypothesis testing. We conduct our analysis by focusing on distributional scenarios that get gradually close the Gaussian case, which is the case where ICA methods fail to recover the independent components. In terms of statistical properties of the ICA estimators, we find no evidence that a method outperforms all others. We finally present an empirical illustration using US data to identify the effects of government spending and tax cuts on economic activity, thus providing an example where ICA techniques can be used for hypothesis testing.

Sourcing newness: ways of inducing indeterminacy

ABSTRACTThis paper engages with the question of the new as the first stage in what may, at a later time, turn into an innovation. Taking our cue from John Dewey, the new is here interpreted as a consequence of indeterminacy. We study practices that induce indeterminacy in order to ‘source’ the new. Based on findings from a collective research programme, we distinguish three ways of inducing indeterminacy: configuring situations, creating things and risking valuations. For each of these ways of inducing indeterminacy basic variations are described and discussed in greater detail. The three ways of inducing indeterminacy are shown to correspond to a present-centred concept of time that distinguishes the now from a past and a future horizon. The cases presented affirm the claim that the new is not an inevitable consequence of the increasing entanglement of technoscience and the economy but something that needs to be sought for, cared for and actively produced.

What Inferentialism Tells Us About Vagueness in Law

According to a view that founds wide support in philosophy of language and linguistics, the full linguistic content of an authoritative legal sentence is what the author intended to communicate by uttering it in a given context. Intentional content may go beyond literal meaning and contextual content, and has to be used to reduce linguistic indeterminacy in order to make legal communication successful. In the case of vague legal sentences, in particular, intentional content would be the only suitable means to determine whether a borderline case falls under the regulation in question.In this paper I argue that the picture just outlined does not provide a convincing explanation of how legal language works, since it does not consider the peculiar characteristics of institutional legal contexts. I then put forward an alternative account of linguistic content and vagueness in law, based on an inferentialist approach to semantics and pragmatics. On this account vagueness is a feature of language which depends on a specific form of disagreement between the participants in an exchange of reasons. By looking at the linguistic interplay between parties and judge in a legal dispute, the paper shows how vagueness arises and how it is reduced by courts in order to settle the case at issue. Ultimately, I suggest that the recourse to legislative intention in legal interpretation is simply a possible move in a linguistic game on which the content of law depends.

Calculation of interface roughness scattering-limited vertical and horizontal mobilities in InAs/GaSb superlattices as a function of temperature

Superlattice transport has acquired new relevance owing to the current interest in InAs/GaSb and other superlattices (SL) for third-generation infrared detector focal plane arrays. Interface-roughness scattering (IRS) is known to limit carrier mobilities at low temperatures. Whereas horizontal (in-plane) transport measurements are standard, perpendicular transport measurements (across SL layers)—the ones relevant to the operation of infrared sensors—are non-routine and seldom performed; vertical SL transport is also less well studied theoretically. Therefore, we extend our previous work on low-temperature SL transport by studying horizontal and vertical IRS-limited transport in InAs/GaSb SLs as a function of temperature, SL parameters, and the degree of roughness. Electron mobilities are calculated by solving the Boltzmann equation with temperature-dependent bands and carrier screening, and the results are discussed by analyzing the behavior of the relaxation rates and spectral mobilities, defined as mobilities as a function of carrier energy. New computational tools are devised to handle the implicit integral equation for the horizontal relaxation rates. We find that the behavior of the relaxation rates and spectral mobilities undergoes a change for energies below and above the conduction band bandwidth, which dictates the ultimate behavior of mobilities as a function of temperature. The calculated mobilities are found to display a rich variety of behaviors as a function of temperature, either increasing, decreasing, or remaining relatively constant, depending on the correlation length of interface roughness, Λ, and the conduction band bandwidth. Since the horizontal mobility is a double-valued function of Λ, the temperature dependence of mobilities can be used to eliminate this indeterminacy in order to assess the degree of interface roughness.

No Fact of the Matter

Are there questions for which 'there is no determinate fact of the matter' as to which answer is correct? Most of us think so, but there are serious difficulties in maintaining the view, and in explaining the idea of determinateness in a satisfactory manner. The paper argues that to overcome the difficulties, we need to reject the law of excluded middle; and it investigates the sense of 'rejection' that is involved. The paper also explores the logic that is required if we reject excluded middle, with special emphasis on the conditional. There is also discussion of higher order indeterminacy (in several different senses) and of penumbral connections; and there is a suggested definition of determinateness in terms of the conditional and a discussion of the extent to which the notion of determinateness is objective. And there are suggestions about a unified treatment of vagueness and the semantic paradoxes.

On the Difficulty of Detecting Cognitive Uncertainty

Uncertainty surely plays an important role in promoting and directing cognitive growth, but most investigations of children’s reasoning and problem solving have relied on procedures that are poorly suited to reveal the degree to which individuals are certain of the answers they endorse. We examine research on children’s reasoning in the context of obvious indeterminacy in order to assess whether simple modifications of the standard assessment procedures would allow us to monitor subjective certainty more reliably. It is concluded that when we set as our goal the measurement of judgment certainty, major changes in our testing methods are required. Two promising alternatives are considered, and it is hypothesized that once these new procedures are perfected and applied, we will discover that uncertainties are both prevalent and prolonged – that most of what seems to be known at any one time is actually understood only partially and therefore with some degree of uncertainty. It is argued that this is a natural and acceptable situation. Progress requires only a relative degree of confidence and not complete certainty. Persistent, vague uncertainties, on the other hand, provide continuous motivation and sensitization for further discoveries, growth, and development.

The Quadrille of Gender: Casanova's Memoirs by Francois Roustang (review)

124Rocky Mountain Review into an area previously served by women replaced the holistic treatment verified by centuries with men using instruments rarely needed. One thinks of Dr. Slop in Tristram Shandy, who, though originally barred from Tristram's delivery in favor of a midwife, manages to remove the skin from Uncle Toby's hands while demonstrating the advantages of forceps. CHARLES G. DAVIS Boise State University FRANCOIS ROUSTANG. The Quadrille of Gender: Casanova's Memoirs. Trans, by Anne C. Vila. Stanford: Stanford University Press, 1988. 163 p. Roustang offers a provocative analysis ofthe major components ofCasanova's life, emphasizing in particular his hesitation about the differences between the sexes and his fascination with superstitious practices. In chronological sequence Roustang develops the thesis that Casanova attempts to avoid guilt and responsibility for his actions by resorting to dissimulation and deceit and by ridiculing society and its laws in order to drain them of all force. Although Casanova gives the impression ofan unorganized text in The Story of My Life [Memoirs] because hé wished to present his work as the result of chance in a similar way to which he felt his life had been guided, Roustang convincingly contends that the writings have "a physiognomy of striking internal coherence" (2) and "obey calculated rules ofcomposition" (1). He raises Casanova from the level ofa lover to that of a writer worthy ofcritical attention. Roustang uses a classical format with a prelude, an introduction, and twelve chapters of approximate equal length whose titles cryptically capture the progressive thrust of the analysis. They are, in order, "Setting up the Love Scene," "The Perfect Alibi," "The Passage into Horror," "The Irresponsible Runaway," "The Disappearance of the Feminine," "A Uniform on a Whim," "By Magic," "Le Plus Honnête Homme au Monde," "The Quadrille," "The Most Powerful ofMen," "The End ofthe First Act," and "Social Order Through Incest." Interestingly, the two longest chapters are "By Magic," in which he fully carries out his role as a charlatan magician, and "The Quadrille," which highlights his obsession with sexual indiscriminacy and whose heading is borrowed by Roustang in the title of his work. It is in this latter chapter that Casanova completely reverses and confuses gender distinction. A foursome, of which he is a member, carries out a sexual relationship in which each plays changing parts. In this way he underscores his need for gender indeterminacy in order to protect himself and maintain his innocence. He is able to create a feeling of irresponsibility by making his actions the result offate and chance. Roustang succinctly captures Casanova's psyche when he concludes that "he has no sense ofthe tragic side ofexistence, never suspects the consequences of his actions, and certainly does not want to assume responsibility for them" (110). Book Reviews125 Roustang's analysis of the multiple liaisons described in the Memoirs is intelligent and precise. He clearly shows, for example, that the fusion of identities where males are disguised as females, females as males, and mothers as children, helps to absolve Casanova of culpability for he can not be held accountable if everything is uncertain and left to chance. Roustang frequently alludes to Casanova's role as a social revolutionary twisting laws and customs to meet his own needs. He highlights the constant leitmotif of the Memoirs which is that Casanova makes people laugh at authority and ridicules it without ever confronting it directly. Not only does Roustang arouse in the reader a growing interest in Casanova as a rebel, but he offers the rich potential ofunexplored depth in a persona whom many have previously dismissed as a mere lover, and nothing more. It is not until the penultimate chapter of the Memoirs, titled, "The End ofthe First Act," that Casanova finally recognizes himself to be nothing more than a con artist and his life metaphorically ends. He will never again be duped but will purposefully dupe others. Roustang observes that his "power over all women is merely a pale reflection of omnipotence" (133). His imagination is gone; the game is over. He abandons self-delusion and faces the influence of fatality over his life. This change is brought about by a certain Miss Charpillon whom he refers...