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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Social Interactions In Breast Cancer Prevention Among Women In The United States

Gray, Natallia 27 June 2014 (has links)
This dissertation contributes to the field of health economics, which, in the past couple of decades, has substantially increased our understanding of the determinants of human health, health-related behavior, and health care choices. A large body of literature has documented the influence of peer group behavior on individual choices. The purpose of my research is to examine the extent of such a phenomenon in breast cancer preventive behavior. Using Behavioral Risk Factors Surveillance System (BRFSS) surveys from 1993-2008, I measured the effect of other female screening behavior on an individual's decision to have a routine breast cancer screening by calculating the size of a so called social multiplier in mammography. I estimated a vector of social multipliers in the use of annual mammograms by taking the ratio of group-level effects of exogenous explanatory variables to individual-level effects of the same variables. Peer groups are defined as same-aged women living in the same geographical area: county or state. Several econometric methods were used to analyze the effect of social interactions on decision to undergo mammography, including ordinary least squares, fixed effects, the split sample instrumental variable approach, and a falsification test. My results supported the hypothesis that social interactions have an impact on the decision to have a mammogram. For all women over age 40, I found strong evidence of social interactions being associated with individual's education and ethnicity. In addition, the decision for women ages 40-49 to have a screening was subject to peer influence through their place of employment and ownership of health insurance. Finally, for women age 75 and older, being married and aging were the most important channels through which peer group influenced the decision to have a mammogram. This research has important policy implications in the presence of current health care reform that reimburses breast cancer screening at 100%, while rates of mammography receipt remain below the policy goal. Furthermore, I examined the effect of the 2009 United States Preventive Services Task Force change in screening recommendations on screening behavior. I demonstrated an immediate reduction in the receipt of mammography among women of all age groups following the revision of screening guidelines. I found that in 2010, the twelve month mammography receipt decreased by 1.97 (women ages 40-49), 2.20 (ages 50-74), and 3.61 (age 75 and older) percentage points, and the twenty-four months mammography receipt decreased by 1.47 (women ages 40-49), 1.05 (ages 50-74), and 1.92 (age 75 and older) percentage points. Analysis using a two-year follow up period after the revision of screening recommendations provided further support to this conclusion.
2

Essays on the Allocation of Scarce Resources among Competing Ends

Cicala, Steven Joseph 08 June 2015 (has links)
The first chapter of this dissertation evaluates changes in fuel procurement practices by coal- and natural gas-fired electricity generating plants in the United States following state-level legislation that ended cost-of-service regulation. I construct a detailed dataset that links confidential, shipment-level data on the price of virtually all of the fuel delivered to coal- and gas-fired electricity plants in the United States from 1990-2009, with plant-level data on operations and regulatory status. I find the price of coal drops by 12% at deregulated plants relative to matched plants that were not subject to any regulatory change, whereas there was no relative drop in the price of gas. I show how my results lend support to theories of asymmetric information between generators and regulators, regulatory capture, and capital-bias as important sources of distortion under cost-of-service regulation. The second chapter analyses changes in the cost of generating electricity following the introduction of regional wholesale electricity markets. I use proxy methods based on Olley and Pakes (1996); Levinsohn and Petrin (2003) to estimate fuel-specific production functions, and construct the Olley-Pakes productivity index to decompose costs in to within-plant productivity and allocative efficiency changes. I then apply a potential outcomes framework to the derived productivity estimates, allowing the construction of counterfactual costs that explicitly account for permanent differences between market and non-market areas and common transitory shocks. I find that the introduction of market-based dispatch methods has reduced fossil-fuel production costs by upwards of 15%. The third chapter is based on joint work with Roland Fryer and Jorg Spenkuch. We develop a Roy model in which individuals sort into peer groups based on comparative advantage. Two key results emerge: First, when comparative advantage is the guiding principle of peer group organization, the effect of moving a student into an environment with higher-achieving peers depends on where in the ability distribution she falls and the effective wages that clear the social market. As a result, linear in means estimates of peer effects are not identified. We show that the model’s testable prediction in the presence of this confounding issue is borne out in two data sets. / Economics
3

Network effects, conformism and misbehavior in Brazilian classrooms

Santos, Luan Falcão Daniel January 2016 (has links)
SANTOS, Luan Falcão Daniel. Network effects, conformism and misbehavior in Brazilian classrooms. -2016. 79f. Dissertação (mestrado). - Universidade Federal do Ceará, Programa de Pós Graduação em Economia, CAEN, Fortaleza, 2016. / Submitted by Mônica Correia Aquino (monicacorreiaaquino@gmail.com) on 2017-07-28T19:24:46Z No. of bitstreams: 1 2016_dis_lfdsantos.pdf: 1161764 bytes, checksum: 657efde122aaf7a32fa71aa91069e159 (MD5) / Approved for entry into archive by Mônica Correia Aquino (monicacorreiaaquino@gmail.com) on 2017-07-28T19:25:15Z (GMT) No. of bitstreams: 1 2016_dis_lfdsantos.pdf: 1161764 bytes, checksum: 657efde122aaf7a32fa71aa91069e159 (MD5) / Made available in DSpace on 2017-07-28T19:25:16Z (GMT). No. of bitstreams: 1 2016_dis_lfdsantos.pdf: 1161764 bytes, checksum: 657efde122aaf7a32fa71aa91069e159 (MD5) Previous issue date: 2016 / For understanding how networks a ect the behavior of individuals, speci - cally the behavior os students in the last year of high school inside the classroom, we estimate a model of Network e ects, the Local-average model for two behavioral variables: doing an exam without being prepared and cheating in an exam, in order to understand how the behavior of individual's friends a ects his or her behavior. It was found a positive and statistically signi cant e ect for the network e ect of the probability of doing an exam without being prepared, and a positive, but not signi cant e ect for the network e ect of the probability of cheating in an exam. This result shows that policies or actions aiming the reduction of the probability of a student do an exam without being prepared have what is called social multiplier e ect, because besides this policy change the behavior of the student regarding this variable, his or her change of behavior a ects positively the behavior of people in his or her network. / Para entender de que forma as networks afetam o comportamento dos indiv duos, em espec co o comportamento de estudantes no ultimo ano do ensino m edio dentro da sala de aula, estimamos um modelo de Network e ects, o Localaverage Model para duas vari aveis comportamentais: fazer uma prova ou teste sem ter se preparado e colar em uma prova, a m de entender como o comportamento dos amigos de um indiv duo afeta o comportamento do mesmo. Encontrou-se uma efeito positivo e estatisticamente signi cante para o network e ect da probabilidade de se fazer uma prova ou teste sem ter se preparado, e um efeito positivo, mas n~ao signi cante para o network e ect da probabilidade de se colar em uma prova. Este resultado mostra que pol ticas ou a c~oes que visam a redu c~ao da probabilidade de um estudante fazer um exame sem se preparar tem o que se chama social multiplier e ect, pois al em dessa pol tica mudar o comportamento do estudante em rela c~ao a essa vari avel, sua mudan ca de comportamento afeta positivamente o comportamento das pessoas em sua network.
4

Essays on Peer Effects

Mihaly, Kata 23 April 2008 (has links)
<p>This dissertation considers the relationship between peer and individual student interaction. The central finding is that self reported friends play a crucial role in individual behaviors, a role that is more significant than other students in their school. Also, using the network of friendships within a school it is possible to construct new peer effect measures and account for endogenous peer group formation. It is however important to distinguish these peer measures from unobserved individual characteristics that may also influence behavior.</p><p>The first chapter examines the effect of potentially misidentifying the reference group on peer effect estimates. The differential impact of school, grade and friend level peer effects on student decisions to smoke and drink are calculated. Friendship nominations come from the Add Health dataset, where students can list up to 10 friends from the school. The bias due to endogenous peer group formation and simulteneity are considered using various instrumenting strategies. Peer effects are found to be large and significant at the friends level for both delinquency variables. It is possible to show that misidentifying the peer group can result in peer effect estimates that are understated by as much as 40\%.</p><p>The second chapter of the dissertation further examines the role of peer interactions, this time considering the effect of popularity on student academic achievement. Recent work has found a strong positive relationship between these variables. In this chapter I ascertain the robustness of these previous findings to controls for unobserved student heterogeneity using and instrumenting technique and a structural model. The results indicate that popularity influences academic achievement positively in the baseline model. However, instrumenting for popularity or including measures of unobserved student characteristics results in a large drop in the effect of popularity, and leads to a significantly negative coefficient in the majority of cases. Interestingly, popularity influences future earnings and attitudes positively, where this effect is robust to the inclusion of unobserved type. Policy simulations where students are redistributed based on race or income indicate that the predicted number of friendships and popularity fall but academic achievement increases. Since student popularity increases happiness and earnings, the overall effect of the redistribution policies have to be considered before implementation.</p> / Dissertation
5

Incentives in the labor market: theory and evidence from the NBA

Sen, Arup 22 March 2016 (has links)
This dissertation uses the institutional setup in the market for NBA players to test important hypotheses about how the labor market functions. Sports markets provide an ideal setting to study economic phenomena because of the wealth of publicly available information on productivity and compensation. In Chapter one, I analyze the effort incentives created by the existence of long-term contracts that guarantee players a wage irrespective of performance. I use a panel of all NBA players from 1999 to 2007 to show that player performance improves as the expiration date of the current contract draws nearer. Players perform ten percent better in the last year of their contract than in the penultimate one, an effect attributable to their interest in gaining a new contract. Despite the adverse effort incentives, teams may still prefer to sign players to multi-period contracts because risk-averse players are willing to accept lower salaries in return for greater security. In Chapter two, I use the fact that the NBA draft provides us with a quasi-natural experiment to analyze the impact of peers on player productivity and earnings. Using information for first round draft picks for a fourteen-year span I find that better teammates have a negative but statistically insignificant effect, on player performance. Teammate quality has a statistically and economically significant adverse impact on player wages. Thus the market appears to penalize players for having better teammates. I focus on the NBA's push to raise the minimum age of entry into the league in Chapter three. This phenomenon seems surprising since one naturally expects employers to encourage and entrenched workers to discourage entry of new workers into the labor market, as this should push wages down. I construct a three-period theoretical model in which the surplus accruing to teams can be higher when entry is restricted, even if the average productivity of NBA players declines. In our setting this outcome is driven by the existence of a fixed wage for rookies, which implies that the rents extracted from new entrants increase when entry is restricted.
6

Foreign-born Peers And Educational Outcome : Evidence From Sweden

Penna, Viktor January 2021 (has links)
Using data on 9th grade students in Sweden for the time period of 2015-2019, this paper estimates a fixed effects model to find out whether the share migrant students has any impact on the grade of foreign-born and native Swedish students. We find that increasing the share of migrant students by one percentage point has a small negative effect on foreign-born students, but find no conclusive evidence from the same effect on Swedish students. Furthermore, we find the effect to be the largest when the share of migrants in a municipality is high, suggesting that redistribution of migrants across municipalities would decrease the negative effect of an increase in migrant students.
7

Three essays on peer effects and applications in environmental economics and family economics

Jixuan Yao (11236569) 06 August 2021 (has links)
This dissertation focuses on analyzing peer effects in household decisions and the diffusion of renewable energy. The first chapter investigates peer effects in two family planning decisions among Chinese households – having a second child and having a son. The second chapter focuses on evaluating environmental policies (tax credit and Corporate Average Fuel Economy standard) on the diffusion of electric vehicles in the US. And the third chapter analyzes peer effects in residential solar panels adoption with a geographic focus on California. In summary, the first and third chapter adopt two structural peer effects models to analyze household behavior under two distinct decision-making context – family planning and solar panels adoption. And the second and third chapter focuses the diffusion of two renewable energy powered products – electric vehicle and solar panels.<br><div><br></div><div>Peer effect measures how much the decision made by an agent (usually refers to an house-hold in this dissertation) is influenced by peers’ decisions under the same decision context. Manski (1993) summarizes the obstacles in identifying peer effects. The first is to separate peer effects with contextual effects, or how much the observed similarity in decision making among peer group members are attributed to similar backgrounds between peers due to endogenous group formation. The second is to separate peer effects with correlated effects, which refers to unobserved household characteristics and are believed to be correlated with each other. We use static and dynamic structural peer effects models to analyze family planning decisions and solar panels adoption decision separately, and these models are capable of disentangling the difficulties mentioned above. For the demand estimation of electric vehicle, we use a random coefficient model which has been broadly used in industrial organization.<br></div><div><br></div><div>The first chapter is motivated by the increasingly unbalanced sex ratio in China. This phenomenon and associated social challenges have been widely documented, though few studies have rigorously investigated the role that peer effects have played in this unbalanced sex ratio. This paper fills this gap by focusing on peer effects in the decision to have a second child, and to have a son. The data we use comes from the 2016 data of China Family Panel Studies, and is a ten-year cohort of women aged 45-54 by 2016; we use a structural discrete choice model to estimate the peer effects. We find that peer choices significantly influence the probability that a family has a second child, but not the probability of having a son. Instead, having a son is largely driven by contextual effects, and in particular, by the education level of one’s peer group.<br></div><div><br></div><div>The second chapter uses the random coefficient model with post-estimation counterfactual analysis to answer two research questions: (1) How much the tax credit has facilitated the diffusion of EV; (2) How much the CAFE standard and penalty level have facilitated the diffusion of EV. We obtain the data from Wards Auto with a years range from 2012 to 2019.We find that the EV market share will decrease by 35.82% if there is no tax credit. CAFE marks down the price of EV in average by 3.4 percent but marks up the price of other types of vehicles by 3.26 percent, whose absolute value far exceeds the CAFE penalty itself. We also find that increasing the penalty level from$55 to$140 per vehicle per mpg below the standard will only increase the EV market share by 0.23% and decrease the non-EV market share by 0.12%.<br></div><div><br></div><div>The third chapter applies a utility-based structural optimal stopping time model developed by de Paula (2009) to analyze solar PV adoption. We use both econometrics model and nonparametric test to support the evidence of peer effects, using public solar PV data obstained from CaliforniaDGStats. And we apply the optimal stopping time model with a confidential data set obtained from PG&E. We find significant peer effects and correlated effects in a case study which contains 20 non-adjacent communities in the suburb of San Jose. And we predicted the adoption rate in this area will increase from 19.77% in 2019 to39.65% in 2029.<br></div>
8

Output Collusion and the Effects of WIC Program and Peers on Breastfeeding Activities

Xu, Xu 14 August 2015 (has links)
The dissertation includes two projects. The first one studies the product market segmentation and output collusion within substitutes; the second one examines the effects of WIC program and peers on breastfeeding activities. In Chapter I, we extend the differentiated product model, first developed by Bowley (1924), by relaxing the assumption that each firm produces only one differentiated product. By doing so, we are able to analyze the potential for collusive market segmentation in a two stage decision framework, first in product space and second in output. We find that when firms cannot coordinate on output, the required discount factor that supports collusive market segmentation is strictly decreasing in product substitutability and is greater than partial output and full collusion. Overall we find that output collusion alone is easier to sustain than collusive product market segmentation. In Chapter II, we first use duration analysis techniques to estimate the effects of WIC participation on breastfeeding activities using a nationwide data. Income ineligible participants are excluded from the sample. The models with and without peer effects variables are both estimated. We find that the prenatal WIC participation status does not have significant effect on breastfeeding activities. Peer effects have significant positive effects on both partial and exclusive breastfeeding durations but not on breastfeeding initiation. The magnitude of the peer effects on each individual is different and depends on the individual’s propensity to breastfeed. The results on peer effects based on the full sample are consistent with the findings from restricted sample. Knowing more than five peers who breastfed increases the probability of initiating by 3.7% and the likelihood of breastfeeding at months 3 and 6 by more than 15%. It also increases the partial and exclusive breastfeeding durations by 9 and 3 weeks, respectively. The results suggest the presence of a social multiplier in breastfeeding. Any exogenous change in breastfeeding behavior due to policy interventions would result in an even greater change due to the bidirectional influences within peer groups. Peer effects play a more important role for breastfeeding duration than initiation.
9

Peer Effects: Evidence from the Students in Taiwan

Wu, Shin-Yi, WU 02 November 2017 (has links)
No description available.
10

Trois essais en finance empirique / Three essays in empirical finance

Zhao, Sujiao 29 October 2014 (has links)
Cette thèse se compose de trois chapitres distincts. Dans le premier chapitre, nous examinons si les facteurs explicatifs de la maturité de la dette précédemment identifiés dans la littérature ont des impacts qui varient en fonction du niveau de maturité de la dette en mettant l'accent sur les cas extrêmes. Nous constatons que les effets des déterminants classiques varient sensiblement en fonction de la distribution de la maturité de la dette. Ces effets sont beaucoup plus faibles pour les percentiles les plus bas et les plus élevés. Cela indique que le risque de refinancement est beaucoup plus contraignant à très court terme et beaucoup moins à très long terme. En revanche, le fait d'avoir accès ou non au financement public accentue ce phénomène d'hétérogénéité de l'impact des déterminants en fonction du niveau de maturité de la dette. Ce dernier point peut s'expliquer par le fait que le risque de refinancement est beaucoup plus important pour les entreprises n'ayant pas accès au financement public. En résumé, nos résultats confirment notre intuition concernant les impacts hétérogènes des déterminants de la maturité de la dette en fonction du niveau de maturité de la dette et en particulier dans les cas extrêmes. Dans le deuxième chapitre, nous examinons les choix de la maturité de la dette des entreprises dans une perspective dynamique. Premièrement, nos résultats mettent en évidence des effets moutonniers. Aussi bien en termes de niveaux de la maturité de la dette qu'en termes de modifications de la maturité de la dette, les entreprises reproduisent le comportement des entreprises du même secteur. Ce comportement moutonnier explique beaucoup plus les variations de la maturité des dettes que les caractéristiques propres des entreprises. Après avoir éliminé l'impact des variations de la structure par terme des taux d'intérêt, ce comportement moutonnier en réponse aux modifications de la maturité de la dette des entreprises du même secteur est encore plus conséquent. Deuxièmement, nous constatons une persistance de niveaux de maturité de la dette dans le temps, notamment pour les entreprises ayant des maturités de la dette très faibles. Le troisième chapitre analyse l'impact du « market timing » sur la maturité de la dette. Nous affirmons que les grandes entreprises affichant des fondamentaux solides ont tendance à émettre des dettes à long terme plutôt qu'à court terme en cas de surévaluation temporaire des titres de ces entreprises. En particulier, pour ce type d'entreprises, l'effet du timing domine celui du comportement moutonnier pendant les périodes de refinancement important. Pour les petites entreprises dont les fondamentaux sont faibles, l'effet du « market timing » est faible, tandis que celui du comportement moutonnier est conséquent. / This dissertation is made of three distinct chapters. The first chapter investigates whether the effects of the previously identified factors vary along the debt maturity spectrum. Special emphasis is place on the extremely cases. Notably, we find that the effects of the conventional determinants vary substantially across the debt maturity distribution. Effect attenuation is observed at the lower and the higher debt maturity percentiles. The mechanism lies in the binding refinancing risk in the short extremes and the lessened refinancing risk in the long extremes. By contrast, the fact that a firm has access to public credit or not accentuates to a larger degree the heterogeneity in the observed effects of the included factors across the debt maturity distribution. This result can be explained by the argument that the refinancing risk is even more binding for firms without access to public credit. Altogether, our findings confirm our intuition concerning the heterogeneous effects of the conventional factors exerted along the debt maturity spectrum, especially for the extreme cases. In the second chapter, we examine debt maturity choices of firms from a dynamic perspective. Our results draw clear implications for a herding effect. Firms herd towards the levels as well as the changes of industry peers' debt maturities. Remarkably, this herding effect explains a much larger proportion of variation in debt maturity adjustment than firms' own characteristics. After eliminating the impact of changes in the yield curve, changes in peer firms' debt maturity policies drives debt maturity dynamics to a larger extent. Meanwhile, we find that debt maturity is persistent over time and that the persistence is primarily attributed to firms with short debt maturities. The third chapter analyzes the impact of market timing. We document that big firms with strong fundamentals attempt to “time” the issuance of long-term debts subsequent to temporary market mispricing. Particularly, for this type of firms, the effect of market timing dominates over that of herding during the periods firms raise large amounts of debts. For small firms with weak fundamentals, the effect of market timing is insignificant whereas the herding evidence is prominent.

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