The Catholic Core of a Celebrated Composition

Despite an undeviating opinion on the subject, his greatest work The Lord of the Rings, is replete with free-floating allegory to Christian characters. Characters and situations that suggest Biblical situations, both narratively and on the level of spirituality and ethics. Each character within biblical text correlates with one or more characters in Tolkien’s work, thus free floating. Tolkien is a devoutly religious author who processes the world, including his own fantasies, through the lens of his faith. While Tolkien draws from different elements of theology in several different ways—such as interchanging his characters to represent various aspects of key Biblical figures—it is clear that Tolkien assigned a moral, free-flowing, yet religious allegorical backbone to his work

Graphs with Plane Outside-Obstacle Representations

An \emph{obstacle representation} of a graph consists of a set of polygonal obstacles and a distinct point for each vertex such that two points see each other if and only if the corresponding vertices are adjacent. Obstacle representations are a recent generalization of classical polygon--vertex visibility graphs, for which the characterization and recognition problems are long-standing open questions. In this paper, we study \emph{plane outside-obstacle representations}, where all obstacles lie in the unbounded face of the representation and no two visibility segments cross. We give a combinatorial characterization of the biconnected graphs that admit such a representation. Based on this characterization, we present a simple linear-time recognition algorithm for these graphs. As a side result, we show that the plane vertex--polygon visibility graphs are exactly the maximal outerplanar graphs and that every chordal outerplanar graph has an outside-obstacle representation.Comment: 12 pages, 7 figure

Self-Regulation through Goal Setting

Goals are an important source of motivation. But little is known about why and how people set them. We address these questions in a model based on two stylized facts from psychology and behavioral economics: i) Goals serve as reference points for performance. ii) Present-biased preferences create self-control problems. We show how goals permit self-regulation, but also that they are painful self-disciplining devices. Greater self-control problems therefore lead to stronger self-regulation through goals only up to a certain point. For severely present-biased preferences, the required goal for self-regulation is too painful and the individual rather gives up.goals, self-control, motivation, time inconsistency, psychology

Goals and Psychological Accounting

We model how people formulate and evaluate goals to overcome self-control problems. People often attempt to regulate their behavior by evaluating goal-related outcomes separately (in narrow psychological accounts) rather than jointly (in a broad account). To explain this evidence, our theory of endogenous narrow or broad psychological accounts combines insights from the literatures on goals and mental accounting with models of expectations-based reference-dependent preferences. By formulating goals the individual creates expectations that induce reference points for task outcomes. These goal-induced reference points make substandard performance psychologically painful and motivate the individual to stick to his goals. How strong the commitment to goals is depends on the type of psychological account. We provide conditions when it is optimal to evaluate goals in narrow accounts. The key intuition is that broad accounts make decisions or risks in different tasks substitutes and thereby create incentives to deviate from goals. Model extensions explore the robustness of our results to different timing assumptions and goal and account revision.quasi-hyperbolic discounting, reference-dependent preferences, loss aversion, self-control, mental accounting, goals

Clustering of Trading Activity in the DAX Index Options Market

Trades in DAX index options with identical maturities cluster around particular classes of strike prices. For example, options with strikes ending on 50 are less traded than options with strikes ending on 00. Clustering is higher when options with close strike prices are good substitutes. The degree of substitution between options with neighboring strikes depends on the strike price grid and options' characteristics. Using regression analysis we analyze the relation between clustering, grid size, and the options' characteristics. To our knowledge this paper is the first to explore how the grid size of strike prices affects options' trading volume.Clustering, Incidental Truncation, Index Options, Volume

Coordination under the Shadow of Career Concerns

To innovate, employees need to develop novel ideas and coordinate with each other to turn these ideas into better products and services. Work outcomes provide signals about employees' abilities to the labor market, and therefore career concerns arise. These can both be 'good' (enhancing incentives for effort in developing ideas) and 'bad' (preventing voluntary coordination). Our model shows how the firm designs its explicit incentive system and organizes work processes to take these conflicting forces into account. The comparative statics results suggest a link between the increased use of teams and recent changes in labor market returns to skills.career concerns, group incentives, knowledge work, reputation, teams

Sphingosine 1-phosphate in renal diseases

Because of its highly bioactive properties sphingosine 1-phosphate (S1P) is an attractive target for the treatment of several diseases. Since the expression of sphingosine kinases as well as S1P receptors was demonstrated in the kidney, questions about the physiological and pathophysiological functions of S1P in this organ have been raised. In this review, we summarize the current state of knowledge about S1P-mediated functions in the kidney. A special focus is put on S1P modulated signal transduction in renal glomerular and tubular cells and consequences for the development and treatment of several kidney diseases, diabetic nephropathy, glomerulonephritis, ischemia-reperfusion injury, as well as for Wilms tumor progression

Motivational Goal Bracketing

It is a puzzle why people often evaluate consequences of choices separately (narrow bracketing) rather than jointly (broad bracketing). We study the hypothesis that a present-biased individual, who faces two tasks, may bracket his goals narrowly for motivational reasons. Goals motivate because they serve as reference points that make substandard performance psychologically painful. A broad goal allows high performance in one task to compensate for low performance in the other. This partially insures against the risk of falling short of ones' goal(s), but creates incentives to shirk in one of the tasks. Narrow goals have a stronger motivational force and thus can be optimal. In particular, if one task outcome becomes known before working on the second task, narrow bracketing is always optimal.goals, multiple tasks, motivational bracketing, self-control, time inconsistency, psychology

An experimental test of career concerns

Holmström’s (1982/99) career concerns model has become an important workhorse for the analysis of agency issues in many fields. The underlying signal jamming argument requires players to use information in a Bayesian way – which may or may not reasonably approximate real-life decision makers’ behavior. Testing this theory with field data is difficult since typically little is known about the information that individuals base their decisions on, and this explains the dearth of empirical studies. We provide experimental evidence that the signal jamming mechanism works in a laboratory setting. Moreover, subjects’ beliefs fit remarkably well requirements imposed by the Bayesian equilibrium concept.incentives, reputation, career concerns, signal jamming, experiments