Getting Beyond the First Result of Solving a Vehicle Routing Problem

The simple vehicle routing problem (VRP) is a common topic of discussion in introductory operations research/management science courses. The VRP can be framed in a variety of ways, and it can be difficult to solve to optimality. For solution purposes, introductory textbooks demonstrate how Excel’s Evolutionary Solver (ES) add-in produces a routing. The ES utilizes a genetic algorithm with a heuristic stopping rule to produce a routing that is not guaranteed to be optimal. Beyond pointing out that search controls, such as maximum execution time, may be extended and followed by restart(s) of ES, textbook treatments do not offer alternative ways to continue the search for a possibly better routing. In this paper, a suite of ways is presented in which students may investigate beyond what ES produces or any other optimality-uncertain VRP solution method. The suite includes perturbation methods and other ways that function within an Excel spreadsheet environment that is popular with students and textbook writers. Because there is no demonstrable feature that confirms optimality, the student problem Solver must settle for a ‘best found’ result as unsettling as it may be. The incertitude is addressed.

Catching Up on Multilevel Modeling (in press, Annual Review of Psychology)

The present review focuses on the use of multilevel models in psychology and other social sciences. We target readers aiming to get up to speed on current best practices and sources of controversy in the specification of multilevel models. We first describe common use cases for clustered, longitudinal, and cross-classified designs, as well as their combinations. Using examples from both clustered and longitudinal designs, we then address issues of centering for observed predictor variables: its use in creating interpretable fixed and random effects, its relationship to endogeneity problems (correlations between predictors and model error terms), and its translation into multivariate multilevel models (using latent centering within multilevel structural equation models). Finally, we describe novel extensions—mixed-effects location–scale models—designed for predicting differential amounts of variability. An online supplement provides suggested introductory textbooks for getting started with multilevel modeling.

Alternative derivations for the fields inside a waveguide

Generally, the longitudinal magnetic field of the transverse electric (TE) wave inside a waveguide is obtained by solving the corresponding Helmholtz wave equation, which further leads to the derivation of the remaining fields. In this paper, we provide an alternative way to obtain this longitudinal magnetic field by making use of one of the Maxwell’s equations instead of directly relying on the Helmholtz wave equation. The longitudinal electric field of the transverse magnetic (TM) wave inside a waveguide can also be derived in a similar fashion. These derivations, which are different from those found in the introductory textbooks on microwave engineering, make the study of waveguides more interesting.

Economic Effects Of The Philosophical Concept Of Community

Introductory textbooks in the History of Economic Thought in use at colleges and universities devote little space to Scholasticism and its influence. Even those that do not start straight with the Physiocrats, Thomas Aquinas appears stuck between Ancient Greek Philosophers and Thomas Mun. Scholasticism with “medieval” economic thought characterized as primitive and focused on “obsolete” issues like usury and just price. Sometimes it is even categorized among the schools that promote State intervention1. This was not the opinion of F.A. Hayek, who appreciated some Scholastic authors as part of the individualistic tradition of Western civilization rooted on the legacy of Ancient Greeks and Romans like Pericles, Thucydides, Cicero and Tacitus2. In his famous Road to Serfdom (1944) F.A. Hayek assumed that Western Civilization had abandoned the right road and the individualistic tradition by the last quarter of the XIX Century. The abandoned road that Hayek refers to is that grounded on Greek, Roman and Medieval tradition and later paved by the ideas of authors like Cobden, Bright, De Tocqueville, Lord Acton, Adam Smith, Hume, Locke or Milton3. Hilaire Belloc4 located the abandonment of the liberal tradition around the same historical time. He would have agreed with most of the names in Hayek´s list, especially Cobden and Bright, but would have added those of radicals like Fox and Cobbett. Regarding more far away sources of Western thought, he would have included Aristotle, Aquinas and the Spanish Jesuit Francisco Suárez.Some of the authors mentioned above represent different traditions in the political philosophy. These traditions could be referred as the “old” and the “new”, following Leo Strauss in the idea of Machiavelli as the turning point. This essay approaches the influence of the political philosophy in the changes referred by Hayek and Belloc by examining the differences between the old and the new concept of community.

Is the linguists’ View of Prescriptive Grammar Reductionist? (A Re-examination of the Accusations Made against the Prescriptive Tradition)

This paper seeks to intellectually stimulate researchers who are interested in the history of grammar and the long-standing debate about prescriptivism. Contrary to popular belief, there are scholars who still put forward arguments about the significant role played by prescriptive grammar in the development of Modern Standard English. Such counter-arguments are usually absent in many introductory textbooks to linguistics, which portray prescriptive grammar in a negative light. Nonetheless, only by listening to both sides of the debate, researchers can make a more objective judgment, avoid reductionist views, and encourage students of linguistics to engage in critical thinking. Therefore, the aim of this study is to re-examine the accusations made against prescriptive grammar by investigating various sources that give a different perspective on the origins and significance of the prescriptive tradition. The study has found that there is a strong connection between the prescriptive school of grammar and the development and preservation of Modern Standard English. Instead of being an impediment, the prescriptive approach that began in the 18th Century was a historical necessity at a time when linguistic variations were out of proportion and accepted standards were absent. The founders of this school did a great service to the English-speaking world by their contributions to the creation of a standard variety that has facilitated communication between speakers of diverse dialects of English. Unfortunately, the merits of this school have been buried by blanket accusations that lack careful analysis of what the works of prescriptive grammarians contained. The study has also shown how the dismissal of the prescriptive grammar can have negative outcomes and why it is important to re-examine the allegations made against it by modern linguists.

Global Studies

A review of introductory international relations, international studies, and global studies textbooks reveals that each field defines itself differently: one in terms of its central focus on the diplomatic and strategic relations of states, the second more broadly by including transnational transactions of all kinds, and the third focusing on globalization as both an object of analysis and a lens through which to view nearly all phenomena. However, in reading past the definitional chapters there are clear overlaps—most notably with regard to each introductory textbook’s treatment of globalization. Close examination of recently published introductory textbooks and those well into multiple editions reveals that globalization is treated as a fundamental aspect of each of the three fields. While both International Relations (IR) and International Studies (IS) scholars have contributed significantly to further broadening of both IR and IS in order to become increasingly “global,” other scholars have moved to create a new field of study called Global Studies (GS). This new field of GS developed in the 1990s as scholars from multiple disciplines began to study the many dimensions of globalization. While globalization remains an essentially contested concept, most scholars accept as uncontroversial that it refers to the many strings that connect the world such that pulling on one string in one place will make a change somewhere else. Globalization’s central dynamics include interconnectivity, reconfiguration of space and time, and enhanced mobility. GS is the only field that places the contested concept of globalization at the center of its intellectual initiative.

The Limits and possibilities of history: How a wider, deeper and more engaged understanding of business history can foster innovative thinking

© Academy of Management Learning & Education, 2016. Calls for greater diversity in management research, education, and practice have increased in recent years, driven by a sense of fairness and ethical responsibility, but also because research shows that greater diversity of inputs into management processes can lead to greater innovation. But how can greater diversity of thought be encouraged when educating management students beyond the advocacy of affirmative action and relating the research on the link between multiplicity and creativity? One way is to think again about how we introduce the subject. Introductory textbooks often begin by relaying the history of management. What is presented is a very limited monocultural and linear view of how management emerged. This article highlights how this history may limit the view of management scholars in contrast to the broader perspectives that the histories of other comparable fields, like medicine and architecture, encourage. We discuss how a wider, deeper, and more engaged understanding of management history can foster thinking differently in our field.

The Limits and possibilities of history: How a wider, deeper and more engaged understanding of business history can foster innovative thinking

© Academy of Management Learning & Education, 2016. Calls for greater diversity in management research, education, and practice have increased in recent years, driven by a sense of fairness and ethical responsibility, but also because research shows that greater diversity of inputs into management processes can lead to greater innovation. But how can greater diversity of thought be encouraged when educating management students beyond the advocacy of affirmative action and relating the research on the link between multiplicity and creativity? One way is to think again about how we introduce the subject. Introductory textbooks often begin by relaying the history of management. What is presented is a very limited monocultural and linear view of how management emerged. This article highlights how this history may limit the view of management scholars in contrast to the broader perspectives that the histories of other comparable fields, like medicine and architecture, encourage. We discuss how a wider, deeper, and more engaged understanding of management history can foster thinking differently in our field.

Popular Culture

This review of three introductory textbooks in the field of popular culture published in 2018 and 2019 focuses on the different perspectives they provide on such culture, as a means for understanding its current state and future evolution. It is divided into six sections: 1. Introduction; 2. Pop Culture, People, and Politics; 3. A Pastiche Approach to Cinema; 4. Pop Culture Theories; 5. Pop Culture and the Internet; 6. Conclusion. Pop culture is changing radically today, breaking away from the historical flow that gained momentum in then 1920s, because its delivery through the Internet may be fragmenting its organic textuality. As a distinct form of culture, pop culture crystallized primarily in the US in the first decades of the twentieth century, arguably as a way for young people to contest and openly violate the restrictive social traditions of colonial America through new music, fashions, and overall lifestyles. It spread rapidly and broadly throughout American cities and other areas of the urbanized world—a diffusion made possible by new technologies, such as radio and cinema. From the outset, trends in pop culture influenced aesthetic tastes, politics, and even major musical and literary movements that were once considered to be part of ‘high culture’, gradually obliterating binary distinctions such as high-versus-low in cultural matters. In a phrase, what started out as a lifestyle reaction against puritanical colonial culture became a major source of new aesthetics (new music, new writing, and so on), remaining so ever since. But pop culture may have run its course with the rise of meme culture on the Internet. The books under review here are thus quite significant, not only because they present complementary views of pop culture to a broad audience, but also because we can draw from them a picture of how pop culture is evolving in the digital age and what this might imply for the future of this century-old cultural experiment.

What Students Learn in Economics 101: Time for a Change

We make the case for a shift in what students learn in a first economics course, taking as our exemplar Paul Samuelson’s paradigm-setting 1948 text. In the shadow of the Great Depression, Samuelson made Keynesian economics an essential component of what every economics student should know. By contrast, leading textbooks today were written in the glow of the Great Moderation and the tamed cyclical fluctuations in the two decades prior to 2007. Here, using topic modeling, we document Samuelson’s novelty and the evolution of the content of introductory textbooks since, and we put forward three propositions. First, as was the case in the aftermath of the Great Depression, new problems now challenge the content of our introductory courses; these include mounting inequalities, climate change, concerns about the future of work, and financial instability. Second, the tools required to address these problems, including strategic interaction, limited information, principal–agent models, new behavioral foundations, and dynamic processes including instability and path dependence, are available (indeed widely taught in PhD programs). And third, as we will illustrate by reference to a new open access introductory text, a course integrating these tools into a new benchmark model can be accessible, engaging, coherent and, as a result, successfully taught to first-year students. Deployed to address the new problems, following Samuelson’s example, the new benchmark provides the basis for integrating not only micro- and macroeconomics but also the analysis of both market failures and the limits of government interventions. ( JEL A22, D00, E00).