Spatial housing economics: a survey

This introduction to the Virtual Special Issue surveys the development of spatial housing economics from its roots in neo-classical theory, through more recent developments in social interactions modelling, and touching on the role of institutions, path dependence and economic history. The survey also points to some of the more promising future directions for the subject that are beginning to appear in the literature. The survey covers elements hedonic models, spatial econometrics, neighbourhood models, housing market areas, housing supply, models of segregation, migration, housing tenure, sub-national house price modelling including the so-called ripple effect, and agent-based models. Possible future directions are set in the context of a selection of recent papers that have appeared in Urban Studies. Nevertheless, there are still important gaps in the literature that merit further attention, arising at least partly from emerging policy problems. These include more research on housing and biodiversity, the relationship between housing and civil unrest, the effects of changing age distributions - notably housing for the elderly - and the impact of different international institutional structures. Methodologically, developments in Big Data provide an exciting framework for future work

Une course sans répit : l’évolution des paramètres des candidats à la résidence en oto-rhino-laryngologie – chirurgie cervico-faciale au fil du temps

Background: There has been an increasing number of Canadian medical graduates who have gone unmatched in the residency selection process. Medical students have been engaging in extracurricular activities outside the formal curriculum which may help to distinguish themselves from their peers in the selection process. To understand how competitiveness in residency selection shapes applicant demographic characteristics and behaviours, this study set out to explore the demographic characteristics and prevalence of reported extra-curricular activities by applicants to Canadian Otolaryngology – Head & Neck Surgery (OTL-HNS) residency across time. Methods: A retrospective, descriptive study reviewed specific sections of the curriculum vitae (CV) of applicants to OTL-HNS programs in Canada.  These sections were self-reported, and included research productivity, involvement in volunteer and leadership activities, membership in associations, and honours or awards granted.  Data was quantified and analyzed descriptively. Results: Between 2013 to 2017, a total of 267 applicants reported a median of 12.6 research publications, 9.6 volunteer activities, six leadership activities, six association memberships and 9.8 honours/awards. Applicants were younger over time, with proportions of applicants over 30 years old decreasing from 56% in 2013 to 9% in 2017. Conclusion: Applicants to Canadian OTL-HNS residency programs are reporting consistently high numbers of extracurricular activities and were of increasingly younger ages. Medical students are investing significant time and energy to pursue these activities which are above and beyond the formal curriculum, possibly contributing to decreased diversity in applicants for competitive residencies, increasing the likelihood of misrepresentation in residency applications, and likely contributing to medical student burnout.Contexte : De plus en plus de diplômés en médecine canadiens demeurent non jumelés à l’issue du processus de sélection des résidents. Certains font des activités hors programme afin de se distinguer de leurs pairs dans le processus de sélection. Pour comprendre comment la compétition dans la sélection de résidents influence les caractéristiques démographiques et les comportements des candidats, cette étude visait à explorer l’évolution des caractéristiques démographiques et la prévalence d’activités hors programme déclarées par les candidats à la résidence en oto-rhino-laryngologie – chirurgie cervico-faciale (ORL-CCF) à travers le temps. Méthodes : Dans le cadre d’une étude rétrospective et descriptive, nous avons parcouru des sections pertinentes du curriculum vitae (CV) des candidats aux programmes d'oto-rhino-laryngologie et chirurgie cervico-faciale au Canada. Ces sections étaient auto-déclarées et comprenaient les activités de recherche, la participation à des activités de bénévolat et de leadership, l'appartenance à des associations et les prix et distinctions obtenus. Les données ont été quantifiées et analysées de manière descriptive. Résultats : Entre 2013 et 2017, un total de 267 candidats ont déclaré une médiane de 12,6 publications de recherche, 9,6 activités de bénévolat, 6 activités de leadership, 6 adhésions à des associations et 9,8 prix et distinctions. Au fil du temps, on observe que les candidats sont de plus en plus jeunes ; ainsi, la proportion de candidats âgés de 30 ans et plus a diminué de 56 % en 2013 à 9 % en 2017. Conclusion : Les candidats aux programmes de résidence en ORL-CCF au Canada déclarent d’une année à l’autre un nombre élevé d'activités hors programme et sont de plus en plus jeunes. Les étudiants en médecine investissent beaucoup de temps et d'énergie dans ces activités qui vont au-delà du programme d'études officiel. Cela pourrait nuire à la diversité des candidats aux programmes de résidence fortement contingentés, augmenter la probabilité de fausses déclarations dans les demandes de résidence et probablement contribuer à l'épuisement professionnel des étudiants en médecin

Analytic Kramer kernels, Lagrange-type interpolation series and de Branges spaces

The classical Kramer sampling theorem provides a method for obtaining orthogonal sampling formulas. In particular, when the involved kernel is analytic in the sampling parameter it can be stated in an abstract setting of reproducing kernel Hilbert spaces of entire functions which includes as a particular case the classical Shannon sampling theory. This abstract setting allows us to obtain a sort of converse result and to characterize when the sampling formula associated with an analytic Kramer kernel can be expressed as a Lagrange-type interpolation series. On the other hand, the de Branges spaces of entire functions satisfy orthogonal sampling formulas which can be written as Lagrange-type interpolation series. In this work some links between all these ideas are established

A detailed analysis of a multi-agent diverse team

In an open system we can have many different kinds of agents. However, it is a challenge to decide which agents to pick when forming multi-agent teams. In some scenarios, agents coordinate by voting continuously. When forming such teams, should we focus on the diversity of the team or on the strength of each member? Can a team of diverse (and weak) agents outperform a uniform team of strong agents? We propose a new model to address these questions. Our key contributions include: (i) we show that a diverse team can overcome a uniform team and we give the necessary conditions for it to happen; (ii) we present optimal voting rules for a diverse team; (iii) we perform synthetic experiments that demonstrate that both diversity and strength contribute to the performance of a team; (iv) we show experiments that demonstrate the usefulness of our model in one of the most difficult challenges for Artificial Intelligence: Computer Go

Destabilising conventions using temporary interventions

Conventions are an important concept in multi-agent systems as they allow increased coordination amongst agents and hence a more efficient system. Encouraging and directing convention emergence has been the focus of much research, particularly through the use of fixed strategy agents. In this paper we apply temporary interventions using fixed strategy agents to destabilise an established convention by (i) replacing it with another convention of our choosing, and (ii) allowing it to destabilise in such a way that no other convention explicitly replaces it. We show that these interventions are effective and investigate the minimum level of intervention needed

Occasional errors can benefit coordination

The chances solving a problem that involves coordination between people are increased by introducing robotic players that sometimes make mistakes. This finding has implications for real-world coordination problems

Assortment optimisation under a general discrete choice model: A tight analysis of revenue-ordered assortments

The assortment problem in revenue management is the problem of deciding which subset of products to offer to consumers in order to maximise revenue. A simple and natural strategy is to select the best assortment out of all those that are constructed by fixing a threshold revenue $\pi$ and then choosing all products with revenue at least $\pi$. This is known as the revenue-ordered assortments strategy. In this paper we study the approximation guarantees provided by revenue-ordered assortments when customers are rational in the following sense: the probability of selecting a specific product from the set being offered cannot increase if the set is enlarged. This rationality assumption, known as regularity, is satisfied by almost all discrete choice models considered in the revenue management and choice theory literature, and in particular by random utility models. The bounds we obtain are tight and improve on recent results in that direction, such as for the Mixed Multinomial Logit model by Rusmevichientong et al. (2014). An appealing feature of our analysis is its simplicity, as it relies only on the regularity condition. We also draw a connection between assortment optimisation and two pricing problems called unit demand envy-free pricing and Stackelberg minimum spanning tree: These problems can be restated as assortment problems under discrete choice models satisfying the regularity condition, and moreover revenue-ordered assortments correspond then to the well-studied uniform pricing heuristic. When specialised to that setting, the general bounds we establish for revenue-ordered assortments match and unify the best known results on uniform pricing.Comment: Minor changes following referees' comment

Improving the performance of bright quantum dot single photon sources using amplitude modulation

Single epitaxially-grown semiconductor quantum dots have great potential as single photon sources for photonic quantum technologies, though in practice devices often exhibit non-ideal behavior. Here, we demonstrate that amplitude modulation can improve the performance of quantum-dot-based sources. Starting with a bright source consisting of a single quantum dot in a fiber-coupled microdisk cavity, we use synchronized amplitude modulation to temporally filter the emitted light. We observe that the single photon purity, temporal overlap between successive emission events, and indistinguishability can be greatly improved with this technique. As this method can be applied to any triggered single photon source, independent of geometry and after device fabrication, it is a flexible approach to improve the performance of solid-state systems, which often suffer from excess dephasing and multi-photon background emission

Pharyngeal Lavage Lymphocytosis in Patients with Obstructive Sleep Apnea: A Preliminary Observation

Background: Upper airway inflammation has been previously demonstrated in obstructive sleep apnea (OSA). However, investigation has been hampered by the necessity of invasive tissue biopsies. Objective: To evaluate the pharyngeal lavage (PHAL) as a new tool to analyze mucosal inflammation in the pharynx of patients with sleep-related disordered breathing. Patients and Methods: 36 patients with a diagnosis of OSA, 14 patients with heavy snorer syndrome (HS) or body position dependent OSA (bd-OSA), and 14 healthy volunteers underwent PHAL. Inflammatory cell counts were compared. Results: Neutrophils were the predominant cells in PHAL in all groups (94.3%60.7%, 98.5%60.6%, 94.3%60.7%, and 96.2%61.4%). OSA patients had significantly increased numbers of lymphocytes (3.2%60.4%) compared to bd-OSA/HS and controls group (0.5%60.1 % and 0.6%60.2%, respectively; P,0.05). Patients with moderate to severe OSA had significantly higher numbers of lymphocytes compared to patients with mild OSA (P,0.05). Conclusions: Data from this study suggest that PHAL is a feasible tool to investigate upper airway inflammation in OSA. In addition, PHAL demonstrates lymphocytic inflammation of the pharynx in OSA patients. Future studies are warranted to evaluate whether PHAL can be used to monitor disease and whether lymphocytic inflammation is affected by OSA treatment