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The Impact of Narcissistic CEOs Running Media Companies on Stock Markets: A Case Study on Elon Musk's Twitter Activity on the Performance of Tesla and Twitter
No full textThesis advisor: Donald CoxDoes a CEO’s narcissism influence the company’s stock? Would it matter if it is a media company? The Efficient Market Hypothesis claims that it matters little given market efficiency, as narcissism has been priced in stock based on the Capital Asset Pricing Model. Existing literature is divided on whether CEO narcissism influences corporate efficiency. This paper refines assumptions on asset pricing by indicating when market inefficiency occurs through panel studies, which the Adaptative Market Hypothesis overlooks. A case study on Elon Musk suggests that the CEO’s narcissism with media involvement creates temporary market inefficiency. This paper innovatively combines an event study of Elon Musk's Twitter activities on Tesla and Twitter with a panel analysis of 17 S&P 500 CEOs. The finding shows that younger and female CEOs, who derive narcissism supply and lead media companies, are more inclined to take risks on stock returns. This result suggests re-evaluating stock market efficiency to include CEO demographics and personality, which extends beyond traditional CAPM models.Thesis (BA) — Boston College, 2024.Submitted to: Boston College. Morrissey School of Arts and Sciences.Discipline: Economics.Discipline: Departmental Honors
Walking on Sunshine: Can Vitamin D and UV-Exposure Explain Opioid Use?
No full textThesis advisor: Donald CoxCan Vitamin D deficiency contribute to opioid use? Though seemingly unrelated substances, the two interestingly mirror each other in effects and metabolism. Vitamin D deficiency can lead to weakness, pain, and depression. Both can interact with addiction receptors in the brain. For these reasons, some evolutionary thinkers argue sunlight, the primary source of Vitamin D, may have emerged as the very first addiction. In this framework, modern opioid use could mirror sun exposure, but without the benefits and regulation which Vitamin D provides. Thus, one's natural Vitamin D levels may be very important to explaining their interactions with opioids. This paper parallels previous medical and epidemiological literature attempting to demonstrate how Vitamin D mediates the strength of opioids. Using 2003--2004 U.S. NHANES prescription use, health, and demographic data for individuals aged 20 to 84, this paper measures the impact of Vitamin D deficiency on the propensity of opioid use. A control function approach is used, leveraging milk consumption to relieve endogeneity concerns in previous studies. Unlike previous findings, we do not observe any significant effect from Vitamin D levels.Thesis (BA) — Boston College, 2024.Submitted to: Boston College. Morrissey School of Arts and Sciences.Discipline: Economics.Discipline: Departmental Honors
Echoes Through the Screen: Social Media Posts' Effect on Public's Pre-Existing Perception on the Healthcare System in China
No full textThesis advisor: Wen FanOver the past summer, China has intensified its anti-corruption efforts in the healthcare sector to improve access, quality, and the negative public perception of the system. In order to understand the effectiveness of these measures, public opinions are crucial. This study examines the effect of social media posts on pre-existing public opinion about the healthcare system, specifically anti-corruption incidents. I sampled 3018 comments from four posts reporting medical anti-corruption incidents on the Chinese social media site Weibo. Results from sentiment analyses indicate a generally positive, but weak level of support for the anti-corruption measures, implying latent doubt about the measures and the healthcare system. Additionally, nearly 31.12% of the comments have an emotional score of zero. This score indicates that respondents either don't have an opinion or think the measures have no effect at all. The study emphasizes the influence of social media on public sentiment towards the medical system in China’s specific socio-political system.Thesis (BA) — Boston College, 2024.Submitted to: Boston College. Morrissey School of Arts and Sciences.Discipline: Sociology.Discipline: Departmental Honors
Accounting For Intersectional Social Identities: Exploring the Statistical Constraints of Models
No full textThesis advisor: Michael RussellIntersectionality theory garners increased attention from researchers interested in understanding the many ways in which oppression impacts lived experiences. In any given present and evolving context, oppression leads to advantages for some social positions and disadvantages for others (Collins & Bilge, 2016; Crenshaw, 1989). Quantitative researchers have attempted to adapt statistical modeling methods to reflect intersectional identities as a proxy for oppression and advantage in their models (Bauer et al., 2021; Schudde, 2018). This dissertation expanded on existing knowledge about the statistical limitations of three methods of modeling intersectional analyses on a continuous outcome variable: 1) Interaction, 2) Categorical, and 3) MAIDHA (multilevel analysis of individual heterogeneity and individual accuracy). Using a Monte Carlo simulation, four demographic data characteristics were manipulated to explore the three models under different scenarios which manipulated: a) the number of demographic categories (and thus intersections); b) the proportion of the sample represented by each demographic group; c) the within-intersectional-group variance in the outcome variable of interest; d) overall sample size. Each scenario and model were replicated 1000 times; results summarized performance of the intersection estimates and effect detection using the outcomes: bias, accuracy, power, type 1 error, and confidence interval coverage.
The fundamental questions that guided this dissertation were:
1. What are the statistical advantages and disadvantages of each model under different demographic data characteristics?
2. In what ways does each model perform differently from one another under each demographic data characteristic condition?
The findings of this dissertation contribute to intersectional quantitative research methods by providing greater insight into how each model performs under more complex data scenarios.Thesis (PhD) — Boston College, 2024.Submitted to: Boston College. Lynch School of Education.Discipline: Measurement, Evaluation, Statistics & Assessment
Developmental Connections Between Socioemotional Well-being and Body Weight in Contexts of Socioeconomic Risks:
No full textThesis advisor: Eric DearingSocioemotional difficulties in childhood have been associated with body weight status and the subsequent development of obesity later in life. However, existing research often overlooks the developmental and dynamic nature of socioemotional functioning. Additionally, there is a lack of systematic examination of this relation across varied aspects of socioeconomic risks. Recent research has highlighted a seemingly paradoxical effect, wherein socioemotional competence is associated with adverse health outcomes among socioeconomically disadvantaged minority youths. Yet, obesity per se has received little attention in this literature. The present dissertation adds to the extant literature by examining links between socioemotional well-being and body weight across socioeconomic contexts. Specifically, the present dissertation provides three empirical papers using secondary analyses of large-scale longitudinal studies of children and adolescents to examine associations between sustained socioemotional competency and body weight. In each paper, the potential moderating role of socioeconomic risks and concerns for robustness across children’s racial/ethnic backgrounds are foci. Paper 1 estimated developmental trajectories of behavior problems from ages 5-6 to 13-14 and assessed whether body mass index (BMI) at ages 21-22 varied by behavior problem trajectory patterns, poverty status, and their interaction. Paper 2 identified self-control trajectories during elementary school, examined their impact on fifth-grade BMI, and explored whether the association between self-control trajectories and BMI differed by poverty status. Lastly, Paper 3 examined associations between self-control across the elementary school years and BMI at the end of elementary school, while allowing these associations by poverty dynamics and exposure to an accumulation of socioeconomic and contextual risks. Across three papers, all analyses were conducted for the entire sample and by racial/ethnic group. Results generally supported the protective role of socioemotional competency in preventing unhealthy body weight, regardless of socioeconomic risks. However, this relation was often less evident for children of color than for White children. These findings are interpreted with concern for the complex roles of disadvantage in children’s lives as pertains to social-emotional adjustment and body weight. The practical significance of the papers is focused on informing intervention efforts based on improved understandings of when, for whom, and under what conditions socioemotional competency is associated with health benefits, risks, or neither.Thesis (PhD) — Boston College, 2024.Submitted to: Boston College. Lynch School of Education.Discipline: Counseling, Developmental and Educational Psychology
TheImpact of Immigration Policy on STEM Degree Classification at US Universities: A Multiple Case Study in New England
No full textThesis advisor: Gerardo L. BlancoMany academic departments at US higher education institutions have either recently begun to offer STEM-degree programs or have reclassified their traditionally non-STEM degree programs as STEM. It has been theorized that departments may do this to recruit F-1 student visa holders, who may be eligible to apply for two-year US work extensions after graduation after graduating from a STEM-designated degree program. However, this theory has not been studied at US higher education institutions. This quantitative study therefore explores the factors that have driven the creation or reclassification of STEM degree programs at six New England universities, focusing on the perceptions and observations of administrators. The findings show that currently-enrolled or recently-graduated F-1 students were most significant in influencing degree program reviews, although international student recruitment influenced and other institutional goals influenced this as well. Surveyed administrators reported that much of their time was spent ensuring compliance with US Department of Homeland Security regulations, which required significant time working with faculty and staff. The findings demonstrated that immigration policy may, by way of F-1 international students, influence academic decisions, suggesting a shift in the role academic faculty have in curriculum.Thesis (MA) — Boston College, 2024.Submitted to: Boston College. Lynch School of Education.Discipline: Educational Leadership and Higher Education
Reconstructing Pleistocene North Atlantic ice sheet and nutrient cycling dynamics using a multi-proxy approach:
No full textThesis advisor: Jeremy ShakunThesis advisor: Tony WangTo better understand ice sheet and nutrient cycling dynamics in the North Atlantic, three geochemical paleo-proxies have been analyzed in Pleistocene marine sediments: cosmogenic nuclides (10Be and 26Al) in ice-rafted debris (IRD), 40Ar/39Ar in IRD, and foraminifera-bound nitrogen isotopes (FB-δ15N). For Chapter 1, we analyzed 10Be and 26Al concentrations in quartz separates of IRD from last-glacial North Atlantic sediments and used these data to constrain the history of Laurentide Ice Sheet (LIS) cover over Canada during the Pleistocene. While LIS history is well constrained since the Last Glacial Maximum (LGM) (~20,000 years ago), there is little evidence available from earlier times. 26Al/10Be ratios are depressed in these samples, the result of long-term decay under cover, which we suggest is best explained by a persistent LIS over much of the last million years. This finding implies that the LIS did not fully disappear during many Pleistocene interglacials, making the current ice-free Holocene interglacial relatively unique.
For Chapter 2, we synthesized 3,762 40Ar/39Ar ages from North Atlantic IRD, including 670 new analyses. 595 of these single-grain analyses come from some of the same sample intervals as Chapter 1. These 40Ar/39Ar ages in IRD, a tracer of IRD provenance, clarify changes in North Atlantic ice sheet extent during the past few glacial cycles. Comparison of 40Ar/39Ar ages with hypothesized ice margins and cosmogenic nuclide data (from Chapter 1) aid in our interpretations. For last-glacial samples, results suggest ice sheets around the basin may have been in a retracted state during Marine Isotope Stage (MIS) 3 (~29-57 ka), an interval of debated ice extent for the LIS. Our synthesis also allows us to present the first complete records 40Ar/39Ar ages in IRD during Heinrich intervals – times when the LIS exhibited iceberg discharge events. These results support the suggestion made by previous work that Heinrich events 3 and 6 are anomalous relative to other intervals. 40Ar/39Ar analyses from earlier glacial periods – the first yet published – highlight that IRD provenance data may be reflecting iceberg survivability in addition to changes in ice extent. Lastly, analyzing cosmogenic nuclides and 40Ar/39Ar ages in IRD from the same sample intervals indicates that both proxies may be used to infer changes in ice sheet provenance; this is the first time cosmogenic nuclides in IRD have been considered in this way.
For Chapter 3, we analyzed FB-δ15N at Site U1313 in North Atlantic samples during the Plio-Pleistocene to reconstruct marine nutrient cycling. In the North Atlantic, nutrient cycling is known to play an important role in regulating surface ocean productivity and CO2 drawdown via photosynthesis. We nevertheless lack a complete understanding of nutrient cycling evolution for the Plio-Pleistocene, during which Northern Hemisphere ice sheets and climate exhibited dramatic fluctuations. We find increasing FB-δ15N values at the transition from the Pliocene to the Pleistocene. Additionally, FB-δ15N values are generally higher during glacials compared to interglacials. We suggest these observations can best be explained by an expansion or increase of N2 fixation in the North Atlantic during warmer intervals (interglacials, Pliocene) and a retraction or decrease of N2 fixation during cold intervals (Pleistocene glacials). Considered alongside previously published paleo-proxy data from Site U1313 we suggest these changes in nutrient cycling reflect climate-driven migrations of the North Atlantic Current.
In Chapter 4, I reflect upon how I have worked to integrate broader impacts into my Ph.D. work. Using a combined approach, I focused on fostering an inclusive environment within paleoclimate research spaces as well as engaging non-scientists in paleoclimate-and Earth science-related activities. These approaches ranged from K-12 partnership activities to mentoring students to more experimental avenues, such as a collaborative art project. I have evaluated the success of this work using a combination of quantitative metrics and subjective assessments. Participating in these efforts was also crucial for reminding me of the importance of making science accessible to everyone as well as for helping me hone my mentorship and science communication skills.Thesis (PhD) — Boston College, 2024.Submitted to: Boston College. Graduate School of Arts and Sciences.Discipline: Earth and Environmental Sciences
On functional dimension of univariate ReLU neural networks:
No full textThesis advisor: Elisenda GrigsbyThe space of parameter vectors for a feedforward ReLU neural networks with any fixed architecture is a high dimensional Euclidean space being used to represent the associated class of functions. However, there exist well-known global symmetries and extra poorly-understood hidden symmetries which do not change the neural network function computed by network with different parameter settings. This makes the true dimension of the space of function to be less than the number of parameters. In this thesis, we are interested in the structure of hidden symmetries for neural networks with various parameter settings, and particular neural networks with architecture . For this class of architectures, we fully categorize the insufficiency of local functional dimension coming from activation patterns and give a complete list of combinatorial criteria guaranteeing a parameter setting admits no hidden symmetries coming from slopes of piecewise linear functions in the parameter space. Furthermore, we compute the probability that these hidden symmetries arise, which is rather small compared to the difference between functional dimension and number of parameters. This suggests the existence of other hidden symmetries. We investigate two mechanisms to explain this phenomenon better. Moreover, we motivate and define the notion of -effective activation regions and -effective functional dimension. We also experimentally estimate the difference between -effective functional dimension and true functional dimension for various parameter settings and different .Thesis (PhD) — Boston College, 2024.Submitted to: Boston College. Graduate School of Arts and Sciences.Discipline: Mathematics
Development of Catalytic Strategies for Chemical Recycling of Polymer:
No full textThesis advisor: Jeffery A. ByersThis dissertation discusses the development of catalytic systems within the context of polymer synthesis and functionalization towards the fulfillment of circular plastic economy. Chapter 1 provides an overview of the limitations of the current mechanical recycling for plastic disposal and two general ways to improve the current system by chemical strategies. Chapter 2 discusses the development of a chemically recyclable thermoplastic elastomer derived from relatively cheap feedstock using redox-switchable polymerization. Chapter 3 describes the application of C-H activation and cross-coupling strategy on commodity polyolefins and the effect on the polymer physiochemical properties by the introduction of functional groups, which has the potential to serve in polymer upcycling. Chapter 4 describes the dehydrogenation of polyethylene (PE) and polypropylene (PP) along with further functionalization of the unsaturated product to demonstrate a route of synthesizing PE/PP compatibilizers from plastic waste. Chapter 5 summarizes our development of simulation-based methods to obtain kinetic information of transition-metal catalyzed copolymerization that may include reversible propagation.Thesis (PhD) — Boston College, 2024.Submitted to: Boston College. Graduate School of Arts and Sciences.Discipline: Chemistry
Examining the Role of Vicarious Minority Stress within a Minority Stress Framework:
Full text linkThesis advisor: V. Paul PoteatSexual and gender minority (SGM) youth and young people have a significantly higher prevalence of mental health challenges than their heterosexual, cisgender peers (Jonas et al., 2022). These disparities are largely linked to disparate experiences of victimization, discrimination, and microaggressions (Meyer, 2003; Mongelli et al., 2019). While most of the literature on this association between minority stress and mental health outcomes focuses on direct experiences of minority stress such as discrimination and victimization, less attention has been given to indirect experiences of minority stress, such as reading about SGM-directed violence on the news or in social media (Hatzenbeuhler et al., 2019; Hicks, 2019; Hughto et al., 2021). Understanding the effects of these vicarious minority stressors, or instances of discrimination and stigma inflicted on someone who shares a minority identity, not in the presence of the individual and without directly targeting the individual, seems increasingly necessary. Recent studies suggest that vicarious experiences of discrimination affect SGM mental well-being across the country (Maduro et al., 2020). The current study sought to extend and test minority stress theory by assessing the impact of minority-specific vicarious stressors - in this case reading about an instance of identity-based community violence - on young peoples’ processing styles and mental health outcomes. In part 1 of the current study, I used an experimental design and quantitative text analysis to assess whether a diverse sample (N = 575) of SGM participants ages 18 - 24 (M = 22.45, SD = 2.22) exhibited differences in affect and processing style when asked to read and respond to a short passage depicting violence directed toward an individual who shares their SGM identities as opposed to those in the control, who read an identical passage with a heterosexual, cisgender subject. Results indicated a greater increase in negative affect, greater likelihood of using negative emotions and anger words, and greater use of self-reference words among participants exposed to the vicarious minority stressor. In part 2, I used structural equation modeling to assess whether self-reported past experiences of minority stress, identity affirmation, and critical consciousness predicted negative affect change and processing style among exposure group participants (N = 402), and whether these in turn predicted depressive symptoms. I found that negative affect change negatively predicted depressive symptoms and use of negative emotions words positively predicted depressive symptoms. Minority stress, identity affirmation, and critical consciousness positively predicted negative emotions words and indirectly predicted depressive symptoms via negative emotions words. Critical consciousness also positively predicted negative affect change and self-reference words, and negatively, indirectly predicted depressive symptoms via negative affect change. Implications to minority stress theory and therapeutic intervention are discussed.Thesis (PhD) — Boston College, 2024.Submitted to: Boston College. Lynch School of Education.Discipline: Counseling, Developmental and Educational Psychology