Thesis advisor: Frank Gollop / My doctoral dissertation consists of three essays in the field of Industrial Organization. The first two consider exclusive dealing contracts between upstream and downstream firms theoretically, while the third measures consumer substitution among geographically differentiated air travel products empirically. In the first chapter I study the ability of an incumbent seller to use exclusive dealing contracts to foreclose efficient entry when there are n downstream buyers, where n can be viewed as a measure of the degree of downstream competition. The effect of downstream competition on the ability of the upstream incumbent to use exclusive contracts anticompetitively depends on whether upstream firms compete over linear or two-part prices. The model also highlights an interesting effect of the sunk cost of upstream entry that is ignored in models with exactly two buyers. In the second chapter I investigate the ability of an incumbent monopolist to exclude a potential entrant via exclusive dealing contracts when these contracts include an agreement over price. I find that a simple entry game yields both exclusionary and entry equilibria. The exclusionary equilibrium is unique, however, under most reasonable assumptions; for example if buyers are downstream competitors, if entry or the marginal cost of the potential entrant are uncertain, or if the incumbent can commit not to compete for unsigned buyers. When buyers compete with one another downstream, the optimal guaranteed price is above (below) the marginal cost of the incumbent when downstream buyers compete over strategic complements (substitutes). In the third and final chapter (co-authored with Kyle Buika) I study the question of geographic market definition in the US airline industry. Though an accurate definition of an economic market is important for any study of industry, there is no rule governing what exactly constitutes a market. To define a market we must ask the question "between which products do consumers substitute,'' knowing that the answer to this question will depend on how "close'' products are to one another in product space, as well as how close they are to one another, and to consumers, in geographic space. We estimate a discrete choice model of air travel demand that uses known information about the locations of products and consumers, which allows us to study substitution patterns among air travel products at different airports. We evaluate the commonly used city-pair and airport-pair definitions of a market for air travel, and conclude that a city-pair is the appropriate definition. We also employ the Hypothetical Monopolist test for antitrust market definition, as defined by the Department of Justice and Federal Trade Commission, and conclude that the relevant geographic market for antitrust analysis is, according to this test, frequently more narrowly defined as an airport-pair. Finally we conduct merger simulations under different market definitions and compare the results to those obtained using our own results, and conclude that accounting for geography is important when studying mergers. / Thesis (PhD) — Boston College, 2011. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.

Greenbelts have been used around the world to control urban growth and to enhance the natural environment of cities since the last century. However, some Latin American governments, influenced by urban renewal principles and modern planning, have implemented greenbelts to beautify and order cities. Much criticism has arisen about the social repercussions of using greenbelts as a way to control citizen behavior, which in many cases has resulted in exclusionary practices, especially of low-income populations. Based on a case study that documents and analyzes the uses and perceptions of residents of the informal settlement, Los Platanitos, of the Parque Nacional Mirador Norte, my research attempts to illuminate the political and social processes shaping urban environmental planning in Santo Domingo in order to understand practices of exclusion and marginalization in contexts marked by socioeconomic inequalities. / text

In recent years, Sweden has seen a vast increase in the number of migrant-background pupils entering the school system. According to official policies, these students should be included in everyday school activities wherever possible. The focus of this study is to investigate when and why this does not happen; with a focus on English lessons in upper primary school, we consider how exclusionary practices are implemented and justified by teachers. Exclusion from classroom activity is a complex, multifaceted topic, and thus needs to be explored from multiple angles. In this study, we adopt a mixed-method approach to data collection, drawing on observation of English classes, interviews with teachers, and analyses of local and national policy documents. We then use the analytical framework of nexus analysis in order to consider how exclusion is a social action, which can be seen as the combination of the historical body, the interaction order, and discourses in place. The main findings of the study show that the reasons pupils get excluded vary between teachers but mostly comes down to teachers' belief in some form of hierarchy between school subjects and that learning Swedish is prioritized for pupils with a migration-background. The implications of these findings are that that teachers do not perceive certain actions as exclusionary but rather view them as standard routines or even as something positive towards the students, which can be hurtful for the excluded pupils and leads to the loss of the socio-cultural learning environments that take place inside the classrooms.