A comparison of UK equity and property duration

This paper considers the duration of property and equity. A general formula for duration of asset classes is derived. It is shown that calculations which assume, usually implicitly, that the flow-through of inflation to cash flow is zero, produce misleadingly high durations for property and equities. These are typically in the range 15 to 25 years. Simulations using the formulae show that property has some bond-like characteristics. The results indicate that, for realistic flow-through rates, equities have a higher duration than property. The flow-through rate is the most important variable in the estimation of equities. Using historical data, equity duration is estimated at 8.65 years and property’s at 3.15 years. These are substantially lower than those commonly cited. If these values can be substantiated, and if higher values are used in practice, portfolio immunisation strategies may need to be reconsidered

Responding to Johnson, Saunders, and Lovano-Kerr

The papers presented by Johnson, Saunders, and Lovano-Kerr are varied in content, but united in the sense of originating within two linked dilemmas. The first dilemma asks whether art educators are to embrace and actively work towards incorporating one currently popular political stance into the education process, or whether we are to devise, as far as we can, a curriculum formed from a synthesis of positions. The second asked whether, in using words like “enculturation” and “social transmission, we mean to the world of the school,” or “to the world at large. These are well-worn dilemmas. Their continuing presence is evidence of past failure to address them successfully, and of their persistence as matters frustrating to the field

Inactivation of pathogens on food and contact surfaces using ozone as a biocidal agent

This study focuses on the inactivation of a range of food borne pathogens using ozone as a biocidal agent. Experiments were carried out using Campylobacter jejuni, E. coli and Salmonella enteritidis in which population size effects and different treatment temperatures were investigate

Conference as Ritual: Structures for the Unsavage Mind

Anthropologists like Victor Turner and Edward Bruner focus their attention on the experience of experiencing. Their approach is to make an initial distinction between behavior, which is noted in other people, and experience, which is personally felt. It is a germane distinction, for anthropologists of their persuasion are more inclined to describe how it felt to be there, rather than what went on. Their stance is closer to phenomenology than to ethnography, and their efforts are concentrated on what gave the occasion its special flavor, its extraordinary character. Their approach suits my present purpose admirably, since my question is, What makes an NAEA conference special

Indentations and Starting Points in Traveling Sales Tour Problems: Implications for Theory

A complete, non-trivial, traveling sales tour problem contains at least one “indentation”, where nodes in the interior of the point set are connected between two adjacent nodes on the boundary. Early research reported that human tours exhibited fewer such indentations than expected. A subsequent explanation proposed that this was because the observed human tours were close to the optimal, and the optimal tours happened to have few indentations. The present article reports two experiments. The first was designed to test the “few indentations” hypothesis under more stringent conditions than previously, by including point sets with two (near) optimal solutions that had a different number of indentations. For these critical point sets, participants produced the optimal solution with fewer indentations significantly more often than the alternative optimal solution. In addition, participants’ solutions started on boundary points significantly more often than by chance. A second experiment tested whether the preference for fewer indentations is the result of a conscious strategy, or the product of the processes that generate a solution. The results supported the latter conclusion. The implications for theories of human tour generation are discussed

An Investigation of Starting Point Preferences in Human Performance on Traveling Salesman Problems

Previous studies have shown that people start traveling sales problem tours significantly more often from boundary than from interior nodes. There are a number of possible reasons for such a tendency: first, it may arise as a direct result of the processes involved in tour construction; second, boundary points may be perceptually more salient than interior points, and selected for that reason; third, starting from the boundary may make the task easier or be more likely to result in a better tour than starting from the interior. The present research investigated each of these possibilities by analyzing start point frequencies in previously unpublished data and by conducting an experiment. The analysis of start points provided some slight but contradictory support for the hypothesis that start selections result from the process of tour construction, but no evidence for the perceptual salience explanation. The experiment required participants to start tours either from a boundary or from an interior point, to test whether there was an effect on the quality of tour construction. No evidence was found that starting point affected either the length of tours or the time required to produce them. However, there was some indication that starting from a central location may be more likely to result in crossed arcs

Heuristics for Comparing the Lengths of Completed E-TSP Tours: Crossings and Areas

The article reports three experiments designed to explore heuristics used in comparing the lengths of completed Euclidean Traveling Salesman Problem (E-TSP) tours. The experiments used paired comparisons in which participants judged which of two completed tours of the same point set was shorter. The first experiment manipulated two factors, the presence/absence of crossed arcs, and the relative areas of the enclosed polygons. Both factors significantly influenced judgments, with the absence of crossings and smaller areas being associated with shorter tours. The second experiment examined the effects of crossings only, and compared stimulus pairs using all possible combinations of no, one, and more than one crossing. The results showed a significant tendency for tours with one or more crossings to be judged longer than tours with none, while tours with more crossings were not judged to be longer than tours with only one. Apparently the mere presence of a crossing is sufficient to cause a tour to be judged as longer. The third experiment examined the effects of area only, and consisted of two parts. In the first part, participants judged which of two tours that differed in area was shorter. The results supported those of the first experiment, by finding that tours with smaller areas tended to be judged as shorter. In the second part of the experiment, participants judged the relative areas of each pair, to determine whether people can reliably differentiate the areas of such complex polygons. The results confirmed that they can, thereby supporting the feasibility of using differences in area as a heuristic to judge relative lengths. The results were discussed in terms of Carruthers’s (2015) proposal of goal modification and the suggestion is made that applying heuristics of the type identified may represent a specific form of goal modification

Categories of insight and their correlates: An exploration of relationships among classic-type insight problems, rebus puzzles, remote associates and esoteric analogies.

A central question in creativity concerns how insightful ideas emerge. Anecdotal examples of insightful scientific and technical discoveries include Goodyear's discovery of the vulcanization of rubber, and Mendeleev's realization that there may be gaps as he tried to arrange the elements into the Periodic Table. Although most people would regard these discoveries as insightful, cognitive psychologists have had difficulty in agreeing on whether such ideas resulted from insights or from conventional problem solving processes. One area of wide agreement among psychologists is that insight involves a process of restructuring. If this view is correct, then understanding insight and its role in problem solving will depend on a better understanding of restructuring and the characteristics that describe it. This article proposes and tests a preliminary classification of insight problems based on several restructuring characteristics: the need to redefine spatial assumptions, the need to change defined forms, the degree of misdirection involved, the difficulty in visualizing a possible solution, the number of restructuring sequences in the problem, and the requirement for figure-ground type reversals. A second purpose of the study was to compare performance on classic spatial insight problems with two types of verbal tests that may be related to insight, the Remote Associates Test (RAT), and rebus puzzles. In doing so, we report on the results of a survey of 172 business students at the University of Waikato in New Zealand who completed classic-type insight, RAT and rebus problems