A Tale of Two Nortons

This paper considers Norton’s Material Theory of Induction. The material theory aims inter alia to neutralize Hume’s Problem of Induction. The purpose of the paper is to evaluate the material theorys capacity to achieve this end. After pulling apart two versions of the theory, I argue that neither version satisfactorily neutralizes the problem

Conceptual Frameworks and Experimental Design in Simultaneous Equations

Using examples drawn from two important papers in the recent literature on weak instruments, we demonstrate how observed experimental outcomes can be pro- foundly inuenced by the dierent conceptual frameworks underlying two exper- imental designs commonly employed when simulating simultaneous equationsSimultaneous equations; Experimental design; Simulation experiment

Small Concentration Asymptotics and Instrumental Variables Inference

Poskitt and Skeels (2005) provide a new approximation to the sampling distribution of the IV estimator in a simultaneous equations model, the approximation is appropriate when the concentration parameter associated with the reduced form model is small. We present approximations to the sampling distributions of various functions of the IV estimator based upon small-concentration asymptotics, and investigate hypothesis testing procedures and confidence region construction using these approximations. We explore the relationship between our work and the K statistic of Kleibergen (2002) and demonstrate that our results can be used to explain the sampling behaviour of the K statistic in simultaneous equations models where identification is weak.simultaneous equations model, IV estimator, weak identification, weak instruments, small-concentration asymptotics

Market Arbitrage of Cash Dividends and Franking Credits

Since 1986 dividend imputation has influenced the ex-dividend day behaviour of Australian share prices. Between 1 April 1986 and 30 May 2004 the Government of the day introduced six major legislative amendments intent on improving the efficiency of the dividend imputation system. This paper explores the impact of dividend imputation, in its various forms, on ex-dividend share price adjustments. We find that only the most recent tax change, which provided full income rebates for unused franking credits, appears to have caused the market to put a statistically significant value on franking credits.Dividend imputation, cash dividends, franking credits, drop-off ratio, tax legislation, structural breaks.

Assessing Instrumental Variable Relevance:An Alternative Measure and Some Exact Finite Sample Theory

focus on the ability of the instrument set to predict a single endogenous regressor, even if there is more than one endogenous regressor in the equation of interest. We propose new measures of instrument relevance in the presence of multiple endogenous regressors, taking both univariate and multivariate perspectives, and develop the accompanying exact finite sample distribution theory in each case. In passing, the paper also explores relationships that exist between the measures proposed here and other statistics that have been proposed elsewhere in the literature. These explorations highlight the close connection between notions of instrument relevance, identification and specification testing in simultaneous equations models.Instrumental variables, weak instruments, relevance, alienation, Wilks’ Lambda.

Method and Apparatus for Removal of Phosphate from Wastewater Streams

Church and Dwight uses a phosphate-containing soap in their latex condom manufacturing process in Chesterfield County, VA. The wastewater streams from this process contain a concentration of phosphate that is over the county limit, costing $100,000/yr for non-optimized disposal. C&D has a need for an in-house method of phosphate removal which does not interfere with current manufacturing or wastewater treatment processes. The focus of the project was precipitation methodology as it is the most economically feasible option for these high concentrations of phosphate; more advanced technologies were considered for a potential final polishing step to remove any residual phosphate. The chemistry for the proposed process was developed by Design of Experiment, utilizing multiple independent and dependent variables. Once optimized, pilot trials were performed in order to verify the lab-scale chemistry. The proposed method of phosphate treatment requires a pH adjustment of the wastewater via sulfuric acid, followed by chemical precipitation via PC-1101 (proprietary coagulant). This solid precipitate is then to be collected utilizing a filter press. Optimal laboratory trials consistently reduced the phosphate concentration by \u3e95%, from 2000-3000 ppm (as Phosphorus) to a nominal 50 ppm (as P). This method will reduce the cost of phosphate treatment by about 40%, with room to further reduce cost via long-term optimization of the pH and coagulant ratio.https://scholarscompass.vcu.edu/capstone/1158/thumbnail.jp

Assessing the Magnitude of the Concentration Parameter in a Simultaneous Equations Model

Poskitt and Skeels (2003) provide a new approximation to the sampling distribution of the IV estimator in a simultaneous equations model. This approximation is appropriate when the concentration parameter associated with the reduced form model is small and a basic purpose of this paper is to provide the practitioner with a method of ascertaining when the concentration parameter is small, and hence when the use of the Poskitt and Skeels (2003) approximation is appropriate. Existing procedures tend to focus on the notion of correlation and hypothesis testing. Approaching the problem from a different perspective leads us to advocate a different statistic for use in this problem. We provide exact and approximate distribution theory for the proposed statistic and show that it satisfies various optimality criteria not satisfied by some of its competitors. Rather than adopting a testing approach we suggest the use of p-values as a calibration device.Concentration parameter, simultaneous equations model, alienation coefficient, Wilks-lambda distribution, admissible invariant test.

Approximating the Distribution of the Instrumental Variables Estimator when the Concentration Parameter is Small.

This paper presents a new approximation to the exact sampling distribution of the instrumental variables estimator in simultaneous equations models. It differs from many of the approximations currently available, Edgeworth expansions for example, in that it is specifically designed to work well when the concentration parameter is small. The approximation is remarkable for the simplicity of its final form, for its accuracy and for its ability to capture those stylized facts that characterize lack of identification and weak instrument scenarios. The development leading to the approximation is also novel in that it introduces techniques of some independent interest not seen in this literature hitherto.concentration parameter, IV estimator, simultaneous equations model, t approximation, weak instruments.

Book review: Ute Eitzenhöfer Schmuck Jewellery by Cornelie Holzach, Wilhelm Lindemann, Marjan Unger. Arnoldsche. ISBN 978-3-89790-406-4

Book review

Report: Going digital: all makers now? craft values in 21st century production

Report on 'All Makers Now?' conference at Falmouth University, 8 - 11 July 2014, organised by the Autonomatic Research Group. The 'All Makers Now?' workshop and conference was amongst many digital technology exhibitions and events taking place across the UK this year. The constituency of the delegates was broad and as the organisers state: ‘this event was aimed at makers and researchers of all shapes and codes including hackers, crafters, inventors, designers, economists, curators and critical theorists.’ All the participants were eager to work out their focus and direction, by exploring how combining crafts and digital skills can bring about new opportunities and debates. The event started with a two day workshop in which the attendees were split into three groups in order to design and make a piece of work to be exhibited at Trelissick House. The teams worked extremely well together, combining skills and knowledge of a variety of digital technologies, from researching online, designing on computer, to programming and finally producing the work with computer-aided machines. The workshop was followed by a two day conference with a huge variety of talks and lectures, leaving all visitors in thought, questioning and relating the digital technologies to their own work, how they will use or avoid technology. Findings 59 is edited by Poppy Porter, Copy Editor Linda Lambert, Advertising Editor Tamizan Savill and designed by Ian Scaife