Manipulation via Capacities Revisited

This paper revisits manipulation via capacities in centralized two-sided matching markets. Sönmez (1997) showed that no stable mechanism is nonmanipulable via capacities. We show that non-manipulability via capacities can be equivalently described by two types of non-manipulation via capacities: non-Type-I-manipulability meaning that no college with vacant positions can manipulate by dropping some of its empty positions; and non-Type-II-manipulability meaning that no college with no vacant positions can manipulate by dropping some of its filled positions. Our main result shows that the student-optimal stable mechanism is the unique stable mechanism which is non-Type-I-manipulable via capacities and independent of truncations. Our characterization supports the use of the student-optimal stable mechanism in these matching markets because of its limited manipulability via capacities by colleges

Fictitious students creation incentives in school choice problems

We address the question of whether schools can manipulate the student-optimal stable mechanism by creating fictitious students in school choice problems. To this end, we introduce two different manipulation concepts, where one of them is stronger. We first demonstrate that the student-optimal stable mechanism is not even weakly fictitious student-proof under general priority structures. Then, we investigate the same question under acyclic priority structures. We prove that, while the student-optimal stable mechanism is not strongly fictitious student-proof even under the acyclicity condition, weak fictitious student-proofness is achieved under acyclicity. This paper, hence, shows a way to avoid the welfare detrimental fictitious students creation (in the weak sense) in terms of priority structures

Games with capacity manipulation : incentives and Nash equilibria

Studying the interaction between preference and capacity manipulation in matching markets, we prove that acyclicity is a necessary and sufficient condition that guarantees the stability of a Nash equilibrium and the strategy-proofness of truthful capacity revelation under the hospital-optimal and intern-optimal stable rules. We then introduce generalized capacity manipulations games where hospitals move first and state their capacities, and interns are subsequently assigned to hospitals using a sequential mechanism. In this setting, we first consider stable revelation mechanisms and introduce conditions guaranteeing the stability of the outcome. Next, we prove that every stable non-revelation mechanism leads to unstable allocations, unless restrictions on the preferences of the agents are introducedStable matching, Capacity, Nash equilibrium, Cycles

Strategic schools under the Boston mechanism revisited

We show that Ergin & Sönmez's (2006) results which show that for schools it is a dominant strategy to truthfully rank the students under the Boston mechanism, and that the Nash equilibrium outcomes in undominated strategies of the induced game are stable, rely crucially on two assumptions. First, (a) that schools need to be restricted to find all students acceptable, and (b) that students cannot observe the priorities set by the schools before submitting their preferences. We show that relaxing either assumption eliminates the strategy dominance, and that Nash equilibrium outcomes in undominated strategies for the simultaneous induced game in case (a) and subgame perfect Nash equilibria in case (b) may contain unstable matchings. We also show that when able to manipulate capacities, schools may only have an incentive to do so if students submit their preferences after observing the reported capacities

Emotional creativity and real-life involvement in different types of creative leisure activities

The role of emotional creativity in practicing creative leisure activities and in the preference of college majors remains unknown. The present study aims to explore how emotional creativity measured by the Emotional Creativity Inventory (ECI; Averill, 1999) is interrelated with the real-life involvement in different types of specific creative leisure activities and with four categories of college majors. Data were collected from 251 university students, university graduates and young adults (156 women and 95 men). Art students and graduates scored significantly higher on the ECI than other majors. Humanities scored significantly higher than technical/economic majors. Five creative leisure activities were significantly correlated with the ECI, specifically, writing, painting, composing music, performing drama, and do-it-yourself home improvement. Keywords: Creativity, Emotional Creativity, Emotions, Creativeness, Affect, Feelings, Leisure Activities, Creative Ability, Artistic Creativity, Creative Thinking, Creativeness, Aging, Cognitive Deficits, Performance. MeSH Headings: Emotions, Creativity, Leisure, Leisure Activities, Hobbies, Recreation, Affect Affective Symptoms, Creativenes

Why 'scaffolding' is the wrong metaphor : the cognitive usefulness of mathematical representations.

The metaphor of scaffolding has become current in discussions of the cognitive help we get from artefacts, environmental affordances and each other. Consideration of mathematical tools and representations indicates that in these cases at least (and plausibly for others), scaffolding is the wrong picture, because scaffolding in good order is immobile, temporary and crude. Mathematical representations can be manipulated, are not temporary structures to aid development, and are refined. Reflection on examples from elementary algebra indicates that Menary is on the right track with his ‘enculturation’ view of mathematical cognition. Moreover, these examples allow us to elaborate his remarks on the uniqueness of mathematical representations and their role in the emergence of new thoughts.Peer reviewe

Embodied cognition: A field guide

The nature of cognition is being re-considered. Instead of emphasizing formal operations on abstract symbols, the new approach foregrounds the fact that cognition is, rather, a situated activity, and suggests that thinking beings ought therefore be considered first and foremost as acting beings. The essay reviews recent work in Embodied Cognition, provides a concise guide to its principles, attitudes and goals, and identifies the physical grounding project as its central research focus

Shared Agency Without Shared Intention

The leading reductive approaches to shared agency model that phenomenon in terms of complexes of individual intentions, understood as plan-laden commitments. Yet not all agents have such intentions, and non-planning agents such as small children and some non-human animals are clearly capable of sophisticated social interactions. But just how robust are their social capacities? Are non-planning agents capable of shared agency? Existing theories of shared agency have little to say about these important questions. I address this lacuna by developing a reductive account of the social capacities of non-planning agents, which I argue supports the conclusion that they can enjoy shared agency. The resulting discussion offers a fine-grained account of the psychological capacities that can underlie shared agency, and produces a recipe for generating novel hypotheses concerning why some agents do not engage in shared agency