Essays in labor economics

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Economics, 2013.Cataloged from PDF version of thesis.Includes bibliographical references.I addressed three questions in Labor Economics, using experimental and quasi-experimental variation to determine causality. In the first chapter, I ask whether playing longer in the NFL increases mortality in retirement. I compared players with very short careers with those with long careers. I also examined mortality for replacement players used briefly during the 1987 players' strike. I find that mortality is 15 percent higher for players with longer careers. This difference is even larger for positions with a high risk of injury. In the second chapter, we use a randomized experiment to evaluate the effects of academic achievement awards for first- and second-year college students studying at a Canadian commuter college. The award scheme offered linear cash incentives for course grades above 70. Awards were paid every term. Program participants also had access to peer advising by upperclassmen. Program engagement appears to have been high but overall treatment effects were small. The intervention increased the number of courses graded above 70 and points earned above 70 for second-year students, but generated no significant effect on overall GPA. Results are somewhat stronger for a subsample that correctly reproduced the program rules. In the third chapter, we examine two questions: (1) What is the value of receiving the first draft pick in the National Basketball Association?, and (2) Do teams lose intentionally to secure higher draft positions? We answer the first question by adjusting for the probability of winning the lottery using a propensity score methodology. The estimates indicate that winning the draft lottery increases attendance by 6 percentage points during the five-year period following the draft. Receiving the first pick is also associated with a small increase in win percentage. To answer the second question, we use a fixed-effects methodology that compares games in which a team can potentially change its lottery odds to games at the end of the season in which these odds are fixed. Since 1968, playoff-eliminated teams have seen around a 5 percentage point increase in win percentage once their lottery odds are fixed. This difference has ballooned above 10 percentage points in more recent years.by Tyler Williams.Ph.D

Tail-Measurable Functions and Their Corresponding Induced Classes, and Some Determinacy Conditions Involving 3-Player Games

In this dissertation, we have two main categories of results. The first is regarding certain point-classes, and the second is regarding 3-player games. The point-classes of Baire Space, \mathcal{N}, in the Borel and Projective Hierarchies, as well as Hausdorff\u27s Difference Hierarchy have been well studied, and there has been much research into further stratifying these hierarchies. One area of particular interest falls in between the point-classes \mathbf{\Pi}_\mathbf{1}^\mathbf{1} and \Delta\left(\omega^2-\mathbf{\Pi}_\mathbf{1}^\mathbf{1}\right). It is well known that the point-classes \beta-\mathbf{\Pi}_\mathbf{1}^\mathbf{1}, for \beta\in\omega^2, stratify this region of the projective hierarchy, with the point-class \bigcup_{\beta\in\omega^2}\beta-\mathbf{\Pi}_\mathbf{1}^\mathbf{1} still falling strictly below \Delta\left(\omega^2-\mathbf{\Pi}_\mathbf{1}^\mathbf{1}\right). Dr. Derrick DuBose developed multiple point-classes, including \left(\kappa\ast\mathbf{\Pi}_\mathbf{1}^\mathbf{1}\right)^\ast for \kappa\in\omega_1. Using determinacy results, DuBose proved that certain of his point-classes further stratify the region between \bigcup_{\beta\in\omega^2}\beta-\mathbf{\Pi}_\mathbf{1}^\mathbf{1} and \Delta\left(\omega^2-\mathbf{\Pi}_\mathbf{1}^\mathbf{1}\right). In this dissertation, we define a new type of classification for functions, which we will refer to as \Gamma Tail-Measurable, as well as bounded \Gamma Tail-Measurable, where \Gamma is a point-class. We also define what we will mean for certain functions and certain sequences to be jointly bounded, that is to say bounded together. Using tail-measurable functions, we define a new manner in which to define certain point-classes of Baire space. When certain bounded tail-measurable functions are used, we will prove that the point-classes produced are exactly the point-classes developed by DuBose. We also will show that by using functions that are tail-measurable (but not bounded), we can produce point-classes that contain all of DuBose\u27s point-classes that fall below \Delta\left(\omega^2-\mathbf{\Pi}_\mathbf{1}^\mathbf{1}\right). Moreover, for certain sets X, defined from tail-measurable functions and sequences that are jointly unbounded, these point-classes contain every set A\subseteq X where A has cardinality at most \aleph_1. Towards our goal, we review certain topological definitions including the definitions of the Borel and Projective Hierarchies, as well as Hausdorff\u27s Difference Hierarchy. We also review some point-classes in the Projective Hierarchy developed by Dr. Derrick DuBose. The study of determinacy of 2-player games on certain game trees is also an active area of research. While the most common game tree is the tree with height \omega and moves from \omega, there have been studies of the determinacy of 2-player games on other game trees, including trees of variable height. Many of the determinacy results use large cardinal hypotheses, such as ``0^# exists\u27\u27, in order to calibrate the strength of the determinacy of certain point-classes in the Projective Hierarchy. It is well known that there exist games with 3 or more players that are not determined in which the payoff sets are of low complexity, e.g., clopen, in the Borel Hierarchy. In this dissertation, we review some definitions concerning 2-player games and determinacy, and review some well-known determinacy results. We then adjust these definitions for 3-player games, and define what we will mean by imposing rules on these games. In effect, imposing a rule on a 3-player game amounts to changing the game tree on which the game is played. We then adjust Wolfe\u27s proof of \Sigma_\mathbf{2}^\mathbf{0} determinacy for 2-player games to prove that 3-player games of a specific form are determined provided that a certain rule is imposed. We also define a special class of 3-player games, which we will refer to as 3213-Games. We will explore some properties of these games, and will define rules that will yield the determinacy of these games

Participation of Zimbabwean female students in university sports.

Masters Degree. University of KwaZulu-Natal, Durban.This study sought to establish the factors affecting the participation of female students in university sports and identify the measures that can help to increase the participation of Zimbabwean female students in university sports. Data was collected through a methodological triangulation of questionnaires, semi-structured interviews and focus group discussions from purposively sampled sports participants (n=125) and non-sports participant female students (n=125), Sports Directors (n=5) and Deans of Students (n=5) drawn from five of the eleven universities that are affiliated to the Zimbabwe Universities Sports Association (ZUSA). The resultant data was analysed by means of quantitative and qualitative procedures using Chi-square with p≤0.05 for quantitative data and by NVIVO 11 Qualitative Data Analysis Software (QDAS). The study established that, although the participation of female students in university sports has improved drastically in the last five years, female students still participate less than their male counterparts. It was also noted that, although institution based constraints have played a part in shaping the current trends of sport participation in Zimbabwean universities, these trends were mainly shaped by the gender stereotypes in the wider Zimbabwean society. The study established that the levels of female student participation can be improved by adopting a national strategy where gender mainstreaming is incorporated in the primary and secondary school curriculum as a means to influence people away from the societal gender stereotypes that have produced the current gender disparities in university sports participation. The findings show that female students derive recreational, material, monetary and psychological benefits. The findings showed that there were no deliberate institutional efforts to try and improve the levels of sport participation by female students in the five case study universities. It was also established that the participation of female students in sports can be improved through the adoption of such institutional measures as; employing female coaches and female sports administrators to be in charge of female student teams, using female role models in campaigns to motivate females to participate in sport, instituting policy measures that redress gender imbalances in sport participation and availing campus accommodation and accessible sporting facilities

Strategic Voting and Social Networks

With the ever increasing ubiquity of social networks in our everyday lives, comes an increasing urgency for us to understand their impact on human behavior. Social networks quantify the ways in which we communicate with each other, and therefore shape the flow of information through the community. It is this same flow of information that we utilize to make sound, strategic decisions. This thesis focuses on one particular type of decisions: voting. When a community engages in voting, it is soliciting the opinions of its members, who present it in the form of a ballot. The community may then choose a course of action based on the submitted ballots. Individual voters, however, are under no obligation to submit sincere ballots that accurately reflects their opinions; they may instead submit a strategic ballot in hopes of affecting the election's outcome to their advantage. This thesis examines the interplay between social network structure and strategic voting behavior. In particular, we will explore how social network structure affects the flow of information through a population, and thereby affect the strategic behavior of voters, and ultimately, the outcomes of elections. We will begin by considering how network structure affects information propagation. This work builds upon the rich body of literature called opinion dynamics by proposing a model for skeptical agents --- agents that distrust other agents for holding opinions that differ too wildly from their own. We show that network structure is one of several factors that affects the degree of penetration that radical opinions can achieve through the community. Next, we propose a model for strategic voting in social networks, where voters are self-interested and rational, but may only use the limited information available through their social network contacts to formulate strategic ballots. In particular, we study the ``Echo Chamber Effect'', the tendency for humans to favor connections with similar people, and show that it leads to the election of less suitable candidates. We also extend this voter model by using boundedly-rational heuristics to scale up our simulations to larger populations. We propose a general framework for voting agents embedded in social networks, and show that our heuristic models can demonstrate a variation of the ``Micromega Law'' which relates the popularity of smaller parties to the size of the population. Finally, we examine another avenue for strategic behavior: choosing when to cast your vote. We propose a type of voting mechanism called ``Sticker Voting'', where voters cast ballots by placing stickers on their favored alternatives, thereby publicly and irrevocably declaring their support. We present a complete analysis of several simple instances of the Sticker Voting game and discuss how our results reflect human voting behavior