VictorJuiz/thesis huggingface dataset:
Essays in Labor Economics and Networks

Network-based connections are pervasive in hiring and mobility patterns. While the theoretical impacts of network connections on the inequality of labor market outcomes are well known (Calvo-Armengol and Jackson, 2004), the empirical magnitude of actual network effects is less certain. A key issue is the difficulty of disentangling the causal effect of network connections from differences in the characteristics of workers in better and worse networks./nIn the first chapter of my dissertation, I study this question using data on freelance workers in Hollywood, who, like many workers in the "freelance economy," are hired for short-term jobs through an informal process that relies in part on previous connections. In such a labor market, the fortunes of an individual worker are closely linked to the careers of key agents who make the hiring decisions for jobs. In Hollywood, workers who know position supervisors who manage more jobs will have more job opportunities. To measure the size of the network effects, I follow cohorts of freelance grips and lighting technicians who first work on a major movie production between 1988 and 2002. I develop two alternative models for the probability that workers are hired on subsequent productions---based on random effects and fixed effects specifications---that incorporate network effects, experience effects, and unobserved heterogeneity. Both models yield large estimates of the effect of experience-based connections on hiring outcomes. I then use the random effects model to develop simulation-based estimates of the fraction of overall inequality in job outcomes for workers in a given cohort that is attributable to inequality in the career success of the key supervisors they met during their initial year of work. I find that about half of the wide dispersion of career outcomes in Hollywood is generated by differences in the career trajectories of these initial key supervisors./nIn the second chapter, I study the asymptotic properties of the fixed effects estimator I employ in the first chapter. The estimator is robust to unobserved heterogeneity across workers and movies. It is based on subgraphs of worker-movie dyads that I call pairs. Inference is non-standard, because pairs within a sample are only independent when they do not share any workers or movies in common. The underlying criterion is a two-sample U-process. I show that the U-statistic derived from the estimator's first order condition is asymptotically equivalent to a certain projection which involves summation over all the worker-movie dyads in the sample. I use this result to derive a consistent estimator of the variance of the estimator.

Advisor: Card, David
Permeable Policymaking: Foreign Firms in the Japanese Political Economy

This dissertation examines the consequences of globalization and trade liberalization for government-business relations in advanced industrial economies. How do the early stages of trade liberalization affect the opportunities for multinational firms to influence the policies of a target country? What factors explain the varying patterns of corporate political activity that we see across different sectors in an economy? In order to answer these questions, I conduct a cross-sectoral analysis of Japan, a country that has historically been notoriously closed to foreign business and investment. Drawing on archival material, market data, newspaper articles, direct observation, and interviews, I examine the influence of foreign firms on the Japanese policymaking process from the immediate post-World War II period to the present. In particular, I focus on case studies of four sectors in which distinctly different patterns of corporate political activity manifest: agriculture, pharmaceuticals, insurance, and information and communications technology./nI find that while foreign firms were initially dependent on their home governments to influence Japanese policy, opportunities for these firms to employee political strategies both independently and in coalition with Japanese partners have increased with the opening of the Japanese economy and society. Furthermore, the manner in which the Japanese market opened has had important consequences for politics; the pattern of internationalization in each sector has shaped foreign firms’ political strategies by defining the scope of potential coalitions and tactics available. In sectors such as agriculture where internationalization in Japan has been minimal, foreign actors’ political strategies remain focused on lobbying their respective home governments, which continue to be the primary conduit for private sector demands. However, in other more internationalized sectors, understanding the precise mix of political strategies used by foreign firms requires investigating the cleavages that internationalization creates in both the home and target countries. In some cases, these cleavages favor the formation of cross-national coalitions, alliances between Japanese and foreign actors who consciously coordinate strategies and pool resources in pursuit of mutual aims. When Japanese actors are divided, foreign firms may be able to form cross-national coalitions and increase their political influence. However, divisions among foreign firms may also complicate the policymaking process, resulting in competing cross-national coalitions or in situations in which foreign firms who have achieved market success in Japan try to shut out all new market entrants, both foreign and Japanese alike.

Advisor: Pempel, T.J.
Curved and anisotropic unstructured mesh generation and adaptivity using the Winslow equations

High-order methods are receiving considerable interest from the computational community because they can achieve higher accuracy with reduced computational cost compared to traditional low-order approaches. These methods generally require unstructured meshes of non-inverted curved elements, and the generation of high-order curved meshes in a robust and automatic way is an important and challenging open problem./nWe present a method to generate high-order unstructured curved meshes by solving the classical Winslow equations using a new continuous Galerkin finite element discretization. This formulation appears to produce high quality curved elements, which are highly resistant to inversion. In addition, the corresponding nonlinear equations can be solved efficiently using Picard iterations, even for highly stretched boundary layer meshes./nAnother challenge that mesh-based methods face is that the discretization of the domain is usually generated before the solution is known, which can lead to large numerical errors or non-convergent schemes. A tool that can be used to overcome this problem is mesh adaptivity. We use the Winslow variable diffusion equations -- which are a variation of the classical form -- to perform curved and anisotropic unstructured mesh adaptivity./nWe use a range of numerical examples to validate our models including complex geometries and stretched boundary layers. We demonstrate the high quality of the generated meshes and the performance of/nthe nonlinear solver. Finally, we present an example of mesh adaptivity for shock capturing when solving the Euler equations of gas dynamics for supersonic flow.

Advisor: Persson, Per-Olof
Parenting and child development in rural Mexico: examination of a large-scale parenting program

Abstract/nParental warmth, responsiveness, and stimulation are associated with positive child development, but it is unclear how parenting quality in early versus later developmental periods contributes to disparities in child cognitive and socioemotional development in low- and middle-income countries (LMIC). This longitudinal study examines the association between early childhood development and parenting quality (low, moderate, high) during infancy and prekindergarten developmental periods.. Parenting quality was defined using scales for “warmth and responsivity”, quantity of “stimulating parenting practices”, and “variety of learning materials” in the home environment, measured using the HOME Inventory in infancy and the Family Care Indicators (FCI) in the prekindergarten period. Child development was assessed in infancy using the Extended Ages and Stages Questionnaire (EASQ) and ASQ Socioemotional scale, and during prekindergarten with the McCarthy Scales of Children’s Abilities. The study sample included 603 children from poor, rural communities in Mexico who were assessed at 4 to 18 months of age and again at 3 to 5 years of age.. The association between parenting quality and child development was examined for differences between indigenous and non-indigenous communities and controlled for child and family demographic characteristics (child age and sex, parent’s educational attainment, and household wealth and crowding). Parenting quality during infancy and prekindergarten were both independently and significantly associated with later child development. However, parenting quality in infancy was no longer significantly associated with later child development after controlling for the effects of child development in infancy. Parental warmth and responsiveness and the availability of learning materials in the home in infancy were significant predictors of child development at 3 to 5 years of age, but parental stimulating practices were not. Conversely, during the prekindergarten period, parental stimulating practices were significant predictors of child development, while the variety of learning materials in the home was not. There were no differences in the association between parenting and child development between indigenous and non-indigenous communities. This study advances the understanding of parenting quality in the early childhood period in LMIC, and among indigenous populations in Mexico.

Advisor: Fernald, Lia CH
Towards an In Vitro Reconstitution of the Alpha-Carboxysome

Many bacteria employ a protein organelle, the carboxysome, to concentrate carbon dioxide/nand catalyze the initial fixation reaction. Only 10 genes from Halothiobacillus/nneapolitanus are sufficient for heterologous expression of carboxysomes in Escherichia coli,/nopening the door to mechanistic analysis of the assembly process of this 200 MDa+/ncomplex. One of these genes, csoS2, produces two highly repetitive intrinsically-disordered/nprotein isoforms and has been shown to be indispensable in carboxysome assembly./nDetailed functional characterization of csoS2, however, has been hindered by the lack of/nunderstanding of how this single gene yields expression of two gene products. In this work,/nwe set out to develop a deeper understanding of CsoS2's biogenesis and its function in α-/ncarboxysome assembly. Using tandem mass spectrometry and biochemical assays, we have/nrevealed that -1 programmed ribosomal frameshifting (- 1 PRF) is responsible for the/ngeneration of a truncated protein with C-terminus translated from the -1 frame, CsoS2A, in/naddition to the full-length protein, CsoS2B. We show for the first time that CsoS2B can be/nindependently produced by mutations of -1 PRF elements and only CsoS2B is necessary for/nthe assembly of H. neapolitanus carboxysomes in native and heterologous hosts. With the/nknowledge of the identity of CsoS2 isoforms, we next investigate the ability of individual/nCsoS2 domains to participate in protein-protein interaction with RuBisCO, the primary/nenzymatic component of the carboxysome. Here, we demonstrate that the 259-aa N-/nterminal domain of CsoS2 multivalently binds RuBisCO, potentially via its short/namphiphatic helices. Finally, based on our findings, we propose a hypothetical model that/ndescribes the formation and maturation of the α-carboxysome. This work illustrates, for/nthe first time, the simultaneous involvement of cotranslational regulation and an/nintrinsically-disordered protein in the assembly of a prokaryotic organelle.

Advisor: Savage, David F
Mechanistic Studies of Catalysis and Molecular Recognition by Synthetic Supramolecular Enzyme Mimics

Chapter 1 – A summary and overview of the application of self-assembled synthetic microenvironment catalysts is presented. The various clusters for which catalytic applications have been reported are introduced together, grouped by mechanism of self-assembly (i.e. hydrogen bond network or metal ligand coordination). The examples of catalysis are then discussed in the context of the nature of charge buildup in the transition state, with neutral reactions presented first, followed by reactions that develop anionic charge in the transition state, and finally reactions that develop cationic charge in the transition state./nChapter 2 – The tetrahedral [Ga4L6]12- supramolecular assembly developed in the Raymond group is shown to catalyze a bimolecular aza-Prins cyclization featuring an unexpected transannular 1,5-hydride transfer. This reaction pathway is promoted by the constrictive binding of the interior microenvironment of the cluster, and is kinetically inaccessible in bulk solution. A thorough investigation of the mechanism of this process is presented, including isotope labeling studies and kinetic analysis, indicating that the rate limiting step of the process is encapsulation of a transiently formed iminium ion and supports the proposed 1,5-hydride transfer pathway. This work represents a striking example of the enzyme-like ability of synthetic microenvironment catalysts to selectively modulate kinetic barriers in order to promote otherwise inaccessible selectivity./nChapter 3 – Catalysis of alkyl-alkyl reductive elimination from high valent transition metal complexes [such as gold(III) and platinum(IV)] by the [Ga4L6]12- Raymond cluster is described. Kinetic experiments delineate an enzyme-like Michaelis-Menten mechanism, with rate accelerations (kcat/kuncat) up to 1.9 × 107. Indirect evidence for the intermediacy of a coordinatively unsaturated encapsulated species is garnered from the observation of several persistent donor-arrested inclusion complexes, including a crystallographically characterized gold(III) cation. The catalysis of reductive elimination is further incorporated into a dual-catalytic cross coupling for which the presence of the supramolecular cluster is necessary in order to achieve efficient turnover, and the full catalytic cycle of this process is elucidated through a series of stoichiometric experiments./nChapter 4 – A novel supramolecular assembly of M4L4 stoichiometry is reported for which the addition of a guest effects an increase from S4- to T-symmetry. A mechanistic investigation of this guest-induced host isomerization revealed that the guest binding occurs by a mechanism similar to the conformational selection model for ligand binding in proteins. A comprehensive study of this simple system provides insight into analogous behavior in biophysics and enzymology, as well as important information to support future efforts in the design of more efficient self-assembled microenvironment catalysts.

Advisor: Toste, F. Dean
Raymond, Kenneth N.
United We Fight: National Unity and Interstate Conflict

Does unity within countries increase conflict between them? In this dissertation, I investigate whether it does using natural experiments. The first essay tests how exogenous surges of nationalism affect state aggression by exploiting a natural experiment that was created by the World Cup. The second essay analyzes whether united government increases state aggression by looking at a similar natural experiment. The third essay considers some of the methodological challenges that arose over the course of this project and draws lessons for future research. Along with shedding new light on the relationship between domestic unity and interstate conflict, this project demonstrates the value of using natural experiments to study international security.

Advisor: Hassner, Ron
Sekhon, Jasjeet
Chiral Acyclic Diaminocarbene Gold(I) Complexes and their Applications in Asymmetric Catalysis

In the span of three decades, asymmetric gold(I) catalysis has transformed from an esoteric curiosity to a powerful synthetic tool. The advancements in gold(I)-catalyzed enantioselective transformations have been critically enabled by a diversity of chiral phosphorus-based ligands, including axially chiral diphosphines and phosphoramidites, among others. The development of chiral carbenes has recently began to augment the library of ligands for gold(I) catalysis. This dissertation will focus on the design and synthesis of chiral acyclic diamino-carbene (ADC) gold(I) complexes, as well as their role in the optimization of a number of synthetic organic transformations.

Advisor: Toste, Francisco D
Electrical Transport in Nanoscale Semiconductors: A Quantum Transport Approach

As predicted by the International Roadmap for Semiconductors, III-V metal-oxide semiconductor field-effect transistors(MOSFETs) are the prime candidates for the 7-nm node and beyond owing to their high mobilities. However, several challenges need to be overcome before III-V materials can replace silicon in extremely scaled devices. As the size of semiconductor devices enters into the nanoscale regime, it is important to understand quantum mechanical effect in electron transport because quantum mechanical effects such as microscopic scattering, quantum mechanical tunneling, carrier confinement and interference effects play a crucial role. We have investigated quantum transport properties of III-V and silicon in nano-scale devices using the non-equilibrium Green’s function (NEGF) formalism coupled with a 20 orbital sp3d5s*-SO tight-binding model. A mode space NEGF approach combined with the full-band WKB model has been introduced to calculate band-to-band tunneling current under the valence band where an atomistic full-band NEGF approach provides a zero current. Self-energy functions for carrier scattering have been implemented within the mode space NEGF formalism to instigate the influence of microscopic scattering effects on quantum transport. This approach has been benchmarked by comparing the scattering rates obtained from Fermi’s golden rule which is widely used in traditional semi-classical calculations. The scattering model is used to study the role of phonon scattering and surface roughness scattering on the carrier transport characteristics of Si and III-V channel devices. In the presence of the electron-phonon interactions, the drain current decreases compared with its ballistic limit, and the current reduction ratio increase as the channel length increases. Effects of indium mole fraction and source/drain doping density (NSD) on the performance of nanoscale III-V MOSFETs are explored and their performance is compared with that of Si transistors. For III-V's, we have found an optimum indium mole fraction and NSD that maximize the Ion/Ioff ratio and Ion by balancing injection velocity and short channel effect.

Advisor: Ramesh, Ramamoorthy
Power System Simulation for Policymaking and Making Policymakers

Power system simulation is a vital tool for anticipating, planning for and ultimately address- ing future conditions on the power grid, especially in light of contemporary shifts in power generation, transmission and use that are being driven by a desire to utilize more environ- mentally responsible energy sources. This dissertation leverages power system simulation and engineering-economic analysis to provide initial answers to one open question about future power systems: how will high penetrations of distributed (rooftop) solar power affect the physical and economic operation of distribution feeders? We find that the overall impacts of distributed solar power (both positive and negative) on the feeders we modeled are minor compared to the overall cost of energy, but that there is on average a small net benefit provided by distributed generation. We then describe an effort to make similar analyses more accessible to a non-engineering (high school) audience by developing an educational video game called “Griddle” that is based on the same power system simulation techniques used in the first study. We describe the design and evaluation of Griddle and find that it demonstrates potential to provide students with insights about key power system learning objectives.

Advisor: Callaway, Duncan
Development of New Imaging Agents for the Study of Cellular Copper Dynamics

Copper is an essential element in biological systems. Its participation as a catalytic and structural cofactor in enzymes that function in biological processes such as energy generation, oxygen transport, cellular metabolism and signal transduction renders it vital for the life of eukaryotic organisms. However, if misregulated, it can cause cellular oxidative damage through the production of highly reactive oxygen species. Consequently, it is not surprising that organisms have developed intricate cellular machineries to tightly regulate the trafficking of copper. The fascinating balance between the functional and pathological roles of copper has significantly motivated the study of the processes involved in the proper management of this metal in the cell by inspection of the total metal content in biological samples and its distribution into static and labile cellular pools. Traditional bulk techniques, in combination with biochemical and genetic methods, have been used probe the static copper pool and provide a general understanding of how cells handle copper ions, allowing for the identification of major proteins and ligands involved in copper homeostasis. Alternatively, molecular imaging provides a complementary, versatile approach that can be used to monitor dynamic fluxes of the labile copper pools in real time with spatial and temporal resolution./nThis dissertation describes the design, synthesis and characterization of new copper-responsive fluorescent sensors in order to expand the available toolbox for molecular imaging of copper dynamics. Application of a novel carbo-rhodol scaffold allowed for the development of the Copper CarboRhodol (CCR) and Copper CarboFluor (CCF) probes, that in combination with additional rhodol platforms extended the available color palette of copper-selective probes. Additionally, the design of unique metal binding motifs with altered ligand architectures, binding geometries and coordination units resulted in the synthesis of new copper-responsive fluorophores. Alteration of the coordination unit and inclusion of a tripodal ligand topology afforded a family of xanthene-based sensors with an assortment of fluorescent responses to copper and ability to sense fluctuations in endogenous, labile copper pools. Finally, development of a modified donor set that increases the number of available donors in the ligand framework was investigated as an alternative strategy to modulate the binding properties of the resulting copper sensors.

Advisor: Chang, Christopher J