The uses and abuses of ‘consensus’ forecasts

Clemen's (1989) review of the forecast-combining literature amply illustrates both the interest in and the importance of this subject. This article stresses the tautological properties of various consensus measures that assure their success relative to most individual forecasts. It confirms the finding of earlier studies that for each specific macroeconomic variable roughly one-third of individual forecasters are more accurate than a consensus. However, each individual does relatively poorly for some variable while the consensus, in contrast, necessarily never fails relative to most individuals. These results, like most previous studies, describe consensus measures that are synthetic constructs derived from a pre-existing set of individual forecasts. Strictly speaking, this contemporaneous consensus is not available to individual forecasters when their forecasts are made. A prior consensus measure, which is in their information sets, was relatively much less accurate than the contemporaneous measure. Nevertheless, a small subset of individual forecasters were generally inferior to the known, prior consensus forecast.     

Bananas and petrol: further evidence on the forecasting accuracy of the ABS ‘headline’ and ‘underlying’ rates of inflation

In the light of the still topical nature of ‘bananas and petrol’ being blamed for driving much of the inflationary pressures in Australia in recent times, the ‘headline’ and ‘underlying’ rates of inflation are scrutinised in terms of forecasting accuracy. A general structural time‐series modelling strategy is applied to estimate models for alternative types of Consumer Price Index (CPI) measures. From this, out‐of‐sample forecasts are generated from the various models. The underlying forecasts are subsequently adjusted to facilitate comparison. The Ashley, Granger and Schmalensee (1980) test is then performed to determine whether there is a statistically significant difference between the root mean square errors of the models. The results lend weight to the recent findings of Song (2005) that forecasting models using underlying rates are not systematically inferior to those based on the headline rate. In fact, strong evidence is found that underlying measures produce superior forecasts. Copyright © 2009 John Wiley & Sons, Ltd.     

The literature and the science of ‘two cultures’ historiography

This paper discusses the historiography of the ‘two cultures’ controversy. C. P. Snow’s lament about the ‘two cultures’, literary and scientific, has inspired a wide range of comment—much of which begins by citing Snow and his thesis, before going on to discuss very different things. This paper focuses upon one strand of this commentary, the historical analysis of the controversy itself. A ‘historical’ analysis is defined here as one that resists the impulse to enter the argument on behalf of Snow or Leavis, to conceive of their argument in the terms that Snow defined, or to invoke their argument as a precursor to some contemporary issue. Instead, a historical interpretation registers distance between that day and this, takes the controversy itself as its object of study, and explores the tensions and associations that came to be packed into those now familiar terms. As the fiftieth anniversary of Snow’s Rede Lecture nears, this approach—rather than the repetition of clichés about the bridging of cultures—offers both analytical perspective on the controversy and interpretive possibilities for its examination.     

Weyl’s ‘agens theory’ of matter and the Zurich Fichte

This paper investigates Hermann Weyl’s reception of philosophical concepts stemming from the German Idealist Johann Gottlieb Fichte. In particular, Weyl’s ‘agens theory’ of matter, which he held around 1925, will be looked at. In the extant literature, the—admittedly also important—influence of Husserl on Weyl has mainly been addressed. Thus, apart from investigating some detailed Fichtean inheritances in Weyl’s concepts of causality, chance and continuity, the general difference which Weyl saw between the philosophies of Fichte and Husserl will also be discussed. For Weyl this is above all a difference between an active constructivism and a rather passive phenomenological seeing (Schau). Further, the paper shows in some detail the way Weyl was drawn into a certain reading of Fichte by his Zurich colleague, the philosopher Fritz Medicus. The methodological frame of the paper is that of Konstellationsforschung, a historical and systematic approach which proves to be particularly fruitful when investigating a (broadly speaking) German Idealist context and which allows special attention to be given to the acting subjects within the constellation under investigation. Conversely, Weyl’s agens theory suggests amendments to this methodology.     

Forecasting with an econometric model: The ‘ragged edge’ problem

In practical econometric forecasting exercises, incomplete data on current and immediate past values of endogenous variables are available. This paper considers various approaches to this ‘ragged edge’ problem, including the common device of treating as ‘temporarily exogenous’ an endogenous variable whose value is known, by deleting it from the set of endogenous variables for whose forecast values the model is solved and suppressing the corresponding structural equation. It is seen that this forecast can be adjusted to coincide with the optimal forecast. The initial discussion concerns the textbook linear simultaneous equation model; extensions to non-linear dynamic models are described.     

Rehabilitating theory: refusal of the ‘bottom-up’ construction of scientific phenomena

In this paper I inquire into Bogen and Woodward’s (1988) data/phenomena distinction, which in a similar way to Cartwright’s construal of the model of superconductivity (1995)—although in a different domain—argues for a ‘bottom-up’ construction of phenomena from data without the involvement of theory. I criticise Bogen and Woodward’s account by analysing their melting point of lead example in depth, which is usually cited in the literature to illustrate the data/phenomenon distinction. Yet, the main focus of this paper lies on Matthias Kaiser’s (1995) case study of the plate tectonic revolution, the most extensive case study that has been put forth to support the bottom-up construction of phenomena. On the basis of new historical evidence, which has been overlooked not only by Kaiser but also by the entire historical literature on the plate tectonic revolution, I demonstrate that phenomena are not constructed from the bottom-up but rather, admittedly counter-intuitively, from the top-down.     

Hermeneutical contributions to the history of science: Gadamer on ‘presentism’

This article examines how Hans G. Gadamer’s philosophical hermeneutics can contribute to contemporary debates on the concept of ‘presentism’. In the field of the history of science, this term is usually employed in two ways. First, ‘presentism’ refers to the kind of historiography which judges the past to legitimate the present. Second, this concept designates the inevitable influence of the present in the interpretation of the past. In this paper, I argue that both dimensions of the relationship between the present and the past are explored by Hans G. Gadamer in Truth and Method and other texts. In the first place, Gadamer’s critique of historicism calls into question the anti-presentist ideal of studying the past for ‘its own sake’. In the second place, Gadamer’s thesis that all understanding inevitably involves some prejudice poses the question of the inherent “present-centredness” of historical interpretations. By examining Gadamer’s hermeneutics, I seek to provide historians with new arguments and perspectives on the question of ‘presentism’.     

Galileo as a ‘bad theologian’: a formative myth about Galileo’s trial

For 150 years after Galileo’s condemnation in 1633, there were many references to the trial, but no sustained, heated or polarized discussions. Then came the thesis that Galileo was condemned not for being a good astronomer but for being a bad theologian (using Scripture to support astronomical hypotheses); it began in 1784–1785 with an apology of the Inquisition by Mallet du Pan in the Mercure de France and the printing in Tiraboschi’s Storia della letteratura italiana of an apocryphal letter attributed to Galileo but forged by Onorato Gaetani. This thesis is not only untenable and false but inverts and subverts the truth; it proved to be long-lasting and widely accepted; so it may be labeled a myth. It was held by such writers as Bergier; Bergier; B; Feller; Cooper; Purcell; Marini; Reumont; Madden and Duhem. Afterwards, it was generally abandoned, its death knell being pope John Paul II’s speeches in 1979–1992. The myth seems to have acted as a catalyst insofar as its creation encouraged the proliferation of pro-clerical accounts and the articulation of pro-Galilean ones, thus making the discussion of Galileo’s trial the cause célèbre it is today.     

The ‘Popperian Programme’ and mathematics: Part II: From quasi-empiricism to mathematical research Programmes

In the first part of this article I investigated the Popperian roots of Lakatos's Proofs and Refutations, which was an attempt to apply, and thereby to test, Popper's theory of knowledge in a field—mathematics—to which it had not primarily been intended to apply. While Popper's theory of knowledge stood up gloriously to this test, the new application gave rise to new insights into the heuristic of mathematical development, which necessitated further clarification and improvement of some Popperian methodological maxims. In the present part I analyze this second phase in the development of Lakatos's Popperian programme in mathematics, and its connection to the methodology of scientific research programmes.     

Comment on ‘Stapp's theorem without counterfactual commitment’

Michael Dickson has examined the ‘could’ version of my nonlocality theorem, and claims to have found a flaw. Several errors in his argument are pointed out. The main problem is that he replaces my locality criterion by a substitute that is too weak to do the job. His justification for making this change is critically flawed by a failure to differentiate my sufficient condition from the converse necessary condition. Nevertheless, Dickson succeeds in deriving all but the final step of my argument. My justification for this final crucial step is discussed here in some detail.     

Revisiting Galison’s ‘Aufbau/Bauhaus’ in light of Neurath’s philosophical projects

In his article entitled ‘Aufbau/Bauhaus’ and related work, Peter Galison explores the connections between the Vienna Circle and the Dessau Bauhaus. Historically, these groups were related, with members of each group familiar with the ideas of the other. Galison argues that their projects are related as well, through shared political views and methodological approach. The two main figures that connect the Vienna Circle to the Bauhaus—and the figures upon which Galison focuses—are Rudolf Carnap and Otto Neurath. Yet, in our view, the connections that Galison develops do not properly capture the common themes between the Bauhaus and Neurath’s philosophical projects. In this paper, we will examine a few of the historical connections between the Dessau Bauhaus and the Vienna Circle, as well as the philosophical connections that Galison draws between these two groups. By examining in greater depth Neurath’s philosophical commitments, we aim to demonstrate that some of these philosophical connections fail to resonate with Neurath’s projects. And, finally, we develop different connections between Neurath’s projects and the Bauhaus. In our view, these new connections between Neurath and the Dessau Bauhaus are both substantive and philosophically interesting.     

‘Physics and fashion’: John Tyndall and his audiences in mid-Victorian Britain

This paper explores how the physicist John Tyndall transformed himself from humble surveyor and schoolmaster into an internationally applauded icon of science. Beginning with his appointment as Professor of Natural Philosophy at the Royal Institution in 1853, I show how Tyndall’s worries about his social class and Irish origins, his painstaking attention to his lecturing performance and skilled use of the material and architectural resources of the Royal Institution were vital to his eventual success as a popular expositor and ambassador for science. Secondly I explore the implications of Tyndall’s ‘popularity’ with respect to debates over the meaning and value of scientific ‘popularisation’. In support of recent work challenging diffusionist models of science communication, I show how Tyndall’s interactions with his audiences illustrate the symbiotic relationship between producer and consumer of ‘popular’ science. By examining the views of Tyndall’s critics—notably the ‘North British’ group of physicists—and his defenders and rivals in the domain of popular scientific lecturing, I show that disputes over Tyndall’s authority reflected anxieties about what constituted popular science and the transient boundaries between instruction and entertainment. The term ‘popularisation’ enjoyed many different uses in these debates, not least of all as a rheorical device with which to either exalt or destroy a scientist’s credibility.     

‘Conservative prejudice’ in the debate over disjunctively distributed life forms

During the thirties and forties, and early fifties, Wegener's ideas were generally rejected as a fantasy—fascinating but false. ‘Ein Machen, a pipe dream, a beautiful fairy story’ chanted the American bandwagon. During these decades of repudiation, arguments which denied continental dispersion passed without scrutiny or test. They were correct a priori because everybody knew that continental drift was wrong.