Agreement toward stability in senior matching markets

A stable matching disrupted by the retirement of workers or the opening, by firms, of positions is said to be firm quasi stable. We prove that, when firms have responsive preferences, the set of stable matchings unanimously preferred by workers to a firm quasi-stable matching has a lattice structure. The result does not necessarily hold when firms have q-substitutable preferences. In this case, we show that the set of stable matchings unanimously preferred by workers to a firm quasi-stable matching contains an element which is unanimously less preferred by workers and most preferred by firms, to any other element in the set: this is the outcome of he Set Offering Algorithm when we take as input the worker quasi-stable matching above mentioned.Senior Mathing Models

Markovian assignment rules

We analyze dynamic assignment problems where agents successively receive different objects (positions, offices, etc.). A finite set of n vertically differentiated indivisible objects are assigned to n agents who live n periods. At each period, a new agent enters society, and the oldest agent retires, leaving his object to be reassigned. We define independent assignment rules (where the assignment of an object to an agent is independent of the way other objects are allocated to other agents), efficient assignment rules (where there does not exist another assignment rule with larger expected surplus), and fair assignment rules (where agents experiencing the same circumstances have identical histories in the long run). When agents are homogenous, we characterize efficient, independent and fair rules as generalizations of the seniority rule. When agents draw their types at random, we prove that independence and efficiency are incompatible, and that efficient and fair rules only exist when there are two types of agents. We characterize two simple rules (type-rank and type-seniority) which satisfy both efficiency and fairness criteria in dichotomous settings.dynamic assignment, finite Markov chains, seniority, promotion rules

Measuring the External Stability of the One-to-One Matching Generated by the Deferred Acceptance Algorithm

In this paper, we consider a one-to-one matching model where the population expands with the arrival of a man and a woman. Individuals in this population are matched, before and after the expansion, according to a version of the deferred acceptance algorithm (Gale and Shapley, 1962) where men propose and women reject or (tentatively or permanently) accept. Using computer simulations of this model, we study how the percentage of matches disrupted (undisrupted) with the expansion of the population is affected when the initial size of the population and the size of correlation in the preferences of individuals change

Markovian assignment rules

We analyze dynamic assignment problems where agents successively receive different objects (positions, offices, etc.). A finite set of n vertically differentiated indivisible objects are assigned to n agents who live n periods. At each period, a new agent enters society, and the oldest agent retires, leaving his object to be reassigned. We define independent assignment rules (where the assignment of an object to an agent is independent of the way other objects are allocated to other agents), efficient assignment rules (where there does not exist another assignment rule with larger expected surplus), and fair assignment rules (where agents experiencing the same circumstances have identical histories in the long run). When agents are homogenous, we characterize efficient, independent and fair rules as generalizations of the seniority rule. When agents draw their types at random, we prove that independence and efficiency are incompatible, and that efficient and fair rules only exist when there are two types of agents. We characterize two simple rules (type-rank and type-seniority) which satisfy both efficiency and fairness criteria in dichotomous settings

Essays on two-sided matching and mechanism design

En esta Disertación Doctoral se analizan problemas económicos en la intersección de las áreas de la Teoría de los Juegos, los Problemas de Emparejamiento y el Diseño de Mecanismos. En particular, he trabajado en el análisis de problemas de emparejamiento en esquemas descentralizados tales como Mercados de Trabajo, Problemas de Admisiones a la Universidad y Problemas Generales de emparejamiento. Recientemente, la investigación sobre estos problemas ha ganado un importante impulso, tanto teórica como empíricamente, debido al estudio de problemas cruciales que no ‘pueden ser analizados bajo los paradigmas clásicos de oferta y demanda. En mi disertación analizo dos problemas principales. Por un lado, hago un análisis de equilibrio de mecanismos descentralizados de emparejamiento con agentes que tomas sus decisiones estratégicamente. Por otro lado, también analizo el problema clásico de emparejamiento en presencia de externalidades, es decir, problemas de emparejamiento donde las preferencias de los agentes dependen de todos los emparejamientos factibles entre agentes y no solo del conjunto de potenciales parejas en un lado opuesto del mercado. Esta disertación se compone de los siguientes tres capítulos, que en sí mismos constituyen contribuciones independientes en esta área de la economía. En el primer capítulo, titulado Incomplete Information and Costly Signaling in College Admissions, analizo el problema de admisión a las universidades con información incompleta acerca de las habilidades de los estudiantes. En este modelo considero, que universidades con calidades observables y estudiantes con información privada se emparejan de acuerdo con un mecanismo descentralizado donde los estudiantes pueden señalizar sus habilidades con señales que son costosas. Bajo estas condiciones, caracterizo un equilibrio simétrico separador del juego inducido por este mecanismo en el cual se maximiza el número de emparejamientos y los mejores estudiantes se matriculan en las mejores universidades. Esta caracterización del equilibrio permite realizar diversos ejercicios de estática comparativa, en ellos se muestra que el cambio de diversos parámetros del modelo afecta asimétricamente a los estudiantes. Por ejemplo, un incremento en el número de estudiantes lleva a que aquellos de baja cualificación reduzcan su inversión en señalización, mientras los de alta cualificación podrían aumentarla. Se observan patrones similares cuando los estudiantes enfrentan un incremento en el número de plazas escolares o un incremento en las calidades de las universidades. Finalmente, se analizan las ganancias del proceso de señalización comparando los pagos de equilibrio de este juego con uno en el que no hay señalización. Entre otros resultados, encuentro que bajo ciertas distribuciones de las habilidades de los estudiantes, una demanda suficientemente alta por las plazas de las universidades llevaría a todos los colegios a tener ganancias positivas. En el segundo capítulo, titulado Many-to-one Matching: externalities and Stability, se analiza la existencia de asignaciones estables en problemas de emparejamiento con externalidades. En este problema, los agentes no solo toman en cuenta sus parejas sino también las parejas de los demás agentes para determinar sus preferencias. Es decir, el emparejamiento de los demás afecta la valoración que yo tengo de mi propio emparejamiento. Una vez que estas externalidades se toman en cuenta, los agentes forman expectativas sobre el conjunto de emparejamientos que ellos consideran admisibles, dichas predicciones son llamadas estimation functions. Dado un conjunto de estimation functions j, un emparejamiento es j-stable si este es admisible para todos los agentes y no es bloqueado por ninguna coalición. Un primer resultado muestra que los emparejamientos j-stables podrían no existir. Aun más, se muestra que ningún conjunto de estimation functions puede asegurar la existencia de emparejamientosj-stable. Además se muestra que un emparejamiento j-stable puede existir, en el caso en el que todos los emparejamientos sean considerados admisibles por todos los agentes, bajo una restrición de las preferencias de los agentes llamada bottom q-substitutability. Finalmente, se analiza también una noción del core en esta clase de problemas de emparejamiento con externalidades llamado el j-core. Se demuestra que el j-core y el conjunto de emparejamientos j-stables siempre coinciden independientemente del conjunto de estimation functions j. Finalmente, en el tercer capítulo, titulado A Simple Decentralized Matching Mechanism in Markets with Couples, se analiza un mecanismo descentralizado de emparejamiento muy simple llamado One Application Mechanism. Bajo este mecanismo, se puede sostener en Equilibrio perfecto en Subjuego (SPE) cualquier emparejamiento estable del mercado. Sin embargo, se encuentra que también es posible sostener emparejamiento inestables en este tipo de equilibrio. Se muestra que solo un tipo muy especial de inestabillidad es admisible en SPE, se argumenta que esta inestabilidad tiene su origen en fallas de coordinación entre los miembros de una pareja. En mi principal resultado, se muestra que el One Application Mechanism implementa en SPE el conjunto de emparejamientos (pairwise) estables de mercados de emparejamiento con parejas. . .This dissertation involves the analysis of economic problems in the intersection of the fields of Game theory, Two-sided Matching and Mechanism Design. In particular, I work on decentralized two-sided matching problems such as job markets, college admissions, marriage problems, etc. In recent years, these economic problems have become crucial, both theoretically and empirically, since there are many important real-world markets where the traditional supply-demand paradigm cannot be applied. My disertation includes the analysis of two main problems. On the one hand, I consider the equilibrium analysis of decentralized matching mechanisms with strategic decision makers. On the other hand, I also analyze two-sided matching problems with externalities where agents’ preferences depend on the complete assignment between workers and firms, students and colleges, etc. and not only on the set of agents on the opposite side of the market. The dissertation consists of the following three chapters that constitute independent contributions in this area. In the first chapter, entitled Incomplete Information and Costly Signaling in College Admissions, I analyze a problem of college admissions with incomplete information about student skills. Colleges with observable qualities and students with private information are matched according to a decentralized mechanism where students can signal their abilities with costly observable signals. I characterize a separating symmetric equilibrium of this game where the number of potential matches is maximized and the best students enroll at the best colleges. My closed form characterization allows to conduct meaningful comparative statics analyses. I show that the effect of a change in the underlying parameters of the model is not symmetric across students. For instance, an increase in the number of students leads the low skilled students to decrease the investment in signaling while the high skilled applicants may increase it. Similar patterns arise when students face a change in the number of school places or college qualities. Finally, I analyze the gains of the signaling process by comparing equilibrium payoffs between this separating equilibrium and a pooling equilibrium with no signaling. Among other results, I show that under certain distributions of the student skills, a large enough demand for school places leads all colleges to get positive gains. In the second chapter, entitled Many-to-one Matching: externalities and Stability, I analyze the existence of stable assignments in matching problems with externalities. In this setting, agents not only care about whom they are matched with but also the partners of the others. Once externalities are considered, agents form expectations on the set of matchings that they consider admissible, such predictions are called estimation functions. Given a set estimation functions j, a matching is j-stable if it is admissible for every agent and not blocked by any coalition. I show that a j-stable matching may not exist. Further, no set of estimation functions assures the existence of j-stable matchings. In the case where all matchings are considered admissible for every agent, a j-stable matching exists under a restriction on agents’ preferences called bottom q-substitutability. Finally, I analyze a notion of the core in matching problems with externalities called the j-core. I find that the j-core and the set of j-stable matchings always coincides for any given set of estimation functions j. Finally, in the third chapter, entitled A Simple Decentralized Matching Mechanism in Markets with Couples, I analyze a simple decentralized matching mechanism called One Application Mechanism. Under this mechanism any stable matching of the market can be achieved in Subgame Perfect Equilibrium (SPE). However, I find that the mechanism may achieve also unstable matchings in SPE. I show that only one special kind of instability is admissible in equilibrium. Further, I argue that this instability only comes from coordination failures between members of couples. My main result shows that the One Application Mechanism implements in SPE the set of pairwise stable matchings of markets with couples. .

Before Exit: Three Essays on Business Exit in Politically and Economically Adverse Environments

This dissertation re-conceptualizes the exit phenomenon in management research by focusing on what precedes exit in times of political and economic turbulence, when firms and entrepreneurs are forced to contemplate unwanted exit as they face multiple threats in their home country. The three essays of this thesis collectively highlight the inadequacy of theories that conceptualize exit as a sudden and complete cessation of activity by showing that exit is an adaptive process that unfolds over time, and across parts of given entities. The first essay contributes to the literature on entrepreneurial exit by exploring how entrepreneurs proactively respond to political and economic turmoil at home that threatens the continuation of their ventures. Relying on the accounts of 27 entrepreneurs, the study inductively reveals two adaptation mechanisms—temporal and partial—that revise the entrepreneur-venture relationship in the aftermath of traumatic events. The second essay adopts a longitudinal and comparative case analysis of 12 firms to explore how adversity at home influences firms’ internationalization paths. The study shows how firms sequentially replace resources, values, and opportunities no longer available in their home market with alternatives that they seek and find in foreign contexts. The essay contributes to the literatures on institutional arbitrage and relocation by revealing how firms identify complementary institutional contexts in international markets, and progressively transition to greener pastures. The third essay is a systematic review of the exit literatures in strategy, international business, and entrepreneurship. The review develops a framework to organize 90 articles that have been systematically coded, and outlines relevant decisions, actions, and processes that may precede exit. The analysis highlights the partiality and temporality of exit as focal dimensions for future research and theorizing on exit in various management disciplines

Cities and Citizenship in Contemporary Latin America and the Caribbean

The Netherlands Association for Latin American and Caribbean Studies (NALACS), in cooperation with the Faculty of Architecture and the Built Environment of the Delft University of Technology, organised the joint conference, ‘Cities and Citizenship in Contemporary Latin America and the Caribbean,’ held on 16-17 June 2016 in Delft, the Netherlands. The 2-day conference embraced a wide range of topics related to urban development and citizenship in Latin America and the Caribbean. Premises of the conference In their pioneering collection of essays ‘Cities and Citizenship’, Holston and Appadurai (1999) as well as other prominent scholars, stressed the importance of cities in the making of modern citizens. At the end of the twentieth century, they demonstrated that urban environments are salient sites for examining the renegotiations of citizenship, democracy, and national belonging. This is arguably particularly the case in contemporary Latin America and the Caribbean, where cities seem to embody the aspirations of citizens and to showcase the best and the worse of their respective societies. It is here that we can observe major opportunities and threats to development, security and human rights, as well as major struggles for rights, inclusion and democracy This conference was organised in 4 tracks Track 1. Cities and Violence: Cities as salient sites where violence and conflict develop and affect the lives of citizens. Track 2. Cities and sustainable development: Cities as salient sites where (spatial) planning and (sustainable) development ideas are applied, and where grassroots and governments alternatingly clash or collaborate in order to simultaneously build cities and structures of citizenship. Track 3. Cities and identity: Cities as salient sites where citizen’s identities and resistances are expressed and repressed. Track 4. Open for suggestions: Cities as salient sites for other themes related to urban life and urban development

Examining The Nexus of Housing Instability and Neighborhood Within New York City (NYC)

Housing instability within the New York City (NYC) area significantly affects the community\u27s well-being. As a robust and growing city, many families in the low-income bracket face the challenge of spending a significant portion of their monthly income toward housing costs (rent, utilities, insurance). With families spending 50% (extreme housing burden) and more of their monthly income to stay in their housing units, various disparities have presented themselves within the housing context. Even before the COVID-19 pandemic in March 2020, families within NYC have struggled to maintain their housing stock. Policy and community-based actions are needed to reduce the burden experienced by low-socioeconomic status households. This study examines the community variables associated with housing burden while analyzing the scope of evictions and legal possessions during COVID-19. Utilizing the social-ecological model as a theoretical framework, the study examines the associations of housing with the livelihood of community residents. The analysis and results bring awareness of the systems which need modification to maintain affordable housing within the NYC area. In reviewing the ethical considerations and hoping to improve equity, this study identifies the community and federal resources low-income residents can utilize to achieve housing justice. The results of this study indicate a need for continued holistic reform within the housing sector of NYC. By engaging stakeholders, policy officials, and housing experts, New Yorkers can experience a better and brighter tomorrow by securing safe and stable housing opportunities

Concentration dynamics and bargaining power: a theory of two-dimensional competition in the agri-food complex

This thesis attempts to explain vertical market interaction within the food chain from a new perspective. It takes a two-stage game-theoretic framework from industrial organisation literature, and extrapolates this into the area of bargaining relationships. In turn, the inter-sectoral paradigm developed is applied to the specific area of agricultural marketing and the conventional wisdom of cooperatives is challenged. The resulting model allows new insights into such issues as countervailing market power, the dynamics of market structure and competition policy. Although the principles have been developed within the context of the U.K. food chain, they are of wider relevance. The conceptual framework developed underlines that in studying bargaining relationships and market structures the economic concept of equilibrium may be better replaced with a broader game-theoretic understanding of the market process

THEY MUDDLED, JUMPED, AND SOMETIMES FLEW: WHEN PROFESSIONAL MEN IN THEIR THIRTIES MAKE A SELF-CHOSEN CAREER CHANGE

THEY MUDDLED, JUMPED, AND SOMETIMES FLEW: WHEN PROFESSIONAL MEN IN THEIR THIRTIES MAKE A SELF-CHOSEN CAREER CHANGEChristopher K. BrayThe research and literature on career and personal transitions have mainly focused on the mid-life career changer. Little research has been conducted with the man in his thirties who decides to make a career change when all seems to be going well. This qualitative Narrative Inquiry study was designed to understand the career transitions of men who make a self-chosen career change while in their thirties. It will seek to understand the fifteen participant's motive to change, process of transition and the lessons/reflections they experienced from the career transition.The study's sample consists of fifteen men who made a decision to change careers in their thirties. Data for the study was obtained through 1-2 hour interviews and also a follow-up interview. The theoretical perspectives for this study center on adult development, career development and personal transitions.The findings emanating from this study include: (1) all participants were compelled to change careers by some external or internal motivation. The specific motivation to change played a role in the success of the vocational transition; (2) the ability to reflect upon the motivations to change, and then apply the lessons learned throughout the transition process is a key aspect of the transition process; (3) choosing to transition careers is more than a career change, it becomes a significant life event; and (4) the importance of a strong support system throughout the transition process