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Observational Data with a Continuous Exposure: Study Design and Outcome Analysis
No full textSubclassification and matching are often used in empirical studies to adjust for observed covariates; however, they are largely restricted to relatively simple study designs with a binary exposure and less developed for designs with a continuous exposure. This thesis contains three papers discussing aspects of study design and outcome analysis with a continuous exposure. The first paper presents a new full match methodology for data with a continuous exposure that achieves good subclass homogeneity, preservation of all study units, dose separation when desired, and control over the size of subclasses. There are two types of empirical studies where matching with a continuous exposure could be useful: studies with a continuous treatment dose and studies with a continuous instrumental variable (IV). The second paper analyzes social mobility data during the COVID-19 pandemic using non-bipartite matching, and proposes a simple randomization test for a structured dose-response relationship. We rejected a primary analysis null hypothesis that stated the social distancing from April 27, 2020, to June 28, 2020, had no effect on the COVID-19-related death toll from June 29, 2020, to August 2, 2020 (p-value \u3c 0.001), and found that it took more reduction in mobility to prevent exponential growth in case numbers for non-rural counties compared to rural counties. The third paper studies how to embed retrospective observational data into a cluster-randomized encouragement experiment using non-bipartite matching, and the associated statistical inference problems. Both the first and third papers are motivated by health outcomes research concerning the effect of intraoperative TEE monitoring during CABG surgery on patients\u27 post-surgery clinical outcomes
The Impact of Host Phenology on Parasite Transmission and Evolution
No full textParasite fitness is tightly controlled by host ecology. The timing of seasonal host activities, or host phenology, likely impacts parasite fitness by determining transmission between infected and uninfected hosts. Changes in host phenology are also expected to drive parasite adaptation in many disease systems, yet the quantitative and qualitative impact of phenology remains under-explored. The overarching goal of this dissertation is to develop theory on how host phenology impacts both parasite transmission and parasite evolution. A novel modelling framework was developed to study how tick life-stage phenology impacts the transmission of Borrelia burgdorferi in the Lyme disease system. This study reveals that slightly asynchronous tick developmental-stage phenology results in high B. burgdorferi fitness compared to synchronous tick activity. Surprisingly, B. burgdorferi is eradicated as asynchrony increases further due to a feedback from mouse population dynamics. A model extension reveals that intermediate parasite virulence is adaptive in the absence of the classic virulence-transmission trade-off for obligate-killer, monocyclic parasites that complete one generation per season. These results suggest that host phenology could drive virulence evolution in some natural systems. A second model extension demonstrates that host phenology can drive multi-season epidemic cycles due to a feedback between host demography and parasite fitness. Short seasons and synchronous host emergence support parasite densities high enough to drive cycling dynamics as parasites adapt. Further, cycling dynamics generate an evolutionary feedback that slows parasite adaptation by preventing adaptive parasite mutants from invading when host densities have been driven down by high parasite densities. A final model extension reveals that host phenology creates multiple evolutionary stable strategies separated by evolutionary repellors for obligate-killer parasites with no constraints on the number of generations they complete per season. Certain environments support both monocyclic and polycyclic parasites, providing clues on the evolutionary origins of both strategies in nature. Overall, this dissertation contributes theory on the impact of host seasonality for parasite fitness and adaptation, providing a framework to study how species respond to seasonal change and predict how disease systems could respond to the impending climate crisis
Algebraic and Geometric Properties of Big Mapping Class Groups
No full textThis thesis investigates mapping class groups of infinite-type surfaces, also called big mapping class groups, by studying their actions on certain graphs whose vertices are arcs and curves on the underlying surface. In particular, we show that the extended mapping class group of any surface with a finite, positive number of punctures is isomorphic to the relative arc graph of that surface; that the mapping class group of any translatable surface is quasi-isometric to that surface\u27s translatable curve graph; and that the mapping class group of a sphere minus a Cantor set is quasi-isometric to that surface\u27s loop graph
Essays in Environmental Economics
No full textIn the first chapter of this dissertation we evaluate potential benefits of drinking water infrastructure investments in the United States. We estimate willingness-to-pay for high-quality drinking water using consumer avoidance behavior in response to health-based drinking water quality violations. To do so we estimate a household-level discrete choice model of drinking water. We find that the average household is willing to pay $162 per year to avoid a one standard deviation decrease in water quality. We additionally find that WTP for bottled water increases in income. We use these estimates to evaluate several counterfactual scenarios. In a scenario in which the United States\u27 water infrastructure deteriorates to the levels of Flint, MI in 2014, we find that US households would be willing to spend 1.4 times the annual US public spending on water infrastructure, suggesting that consumer preferences strongly justify major increases in water infrastructure investments in the United States.The second chapter studies the design of renewable energy portfolios standards (RPSs). We focus on solar energy and analyze two common RPS rules: cross-state trading restrictions and state-specific interim annual targets. Using historically observed RPSs, together with our estimated state-level solar supply curves, we find that allowing for cross-state trading reduces cost by 24% and significantly changes the geographic distribution of new solar installations. Removing interim annual targets over the 2015-2019 period reduces cost by 32% by back-loading installations to later years. These cost reductions become much larger when considering more ambitious RPS targets. Our results suggest that more flexible program design such as allowing for cross-state trading, back-loading interim targets, or banking and borrowing renewable energy credits can avoid escalating costs and preserve the political feasibility of renewable energy standard
Self-Censorship and Strategic Omission in Moral Communication
No full textIn their words and actions, people are motivated to appear morally good, socially conscious, and politically correct. Yet while having a reputation for strong moral character can be extremely valuable, cultivating such a reputation can be a tricky business. Indeed, individuals who advertise their commitment to moral causes or who weigh in on hot-button social issues are often met with skepticism or scorn, and sometimes castigated as disingenuous braggarts or tactless virtue-signalers. To date, work in this area has focused primarily on the ways in which people try to broadcast their morality (e.g., by donating time and money, purchasing cause marketing products, voicing their political opinions online, or boycotting transgressive individuals or brands) and on how such strategies are received by others. By contrast, much less is known about the strategies people use to avoid moral and political communication. I present three essays which examine processes of self-censorship and strategic omission, and which highlight their unexpected costs. The first essay investigates people’s reticence to talk about their charitable giving and develops an intervention to remedy it, with an eye towards boosting word-of-mouth fundraising for nonprofit organizations. The second essay explores people’s discomfort sharing attitude-incongruent facts about charged social issues, even facts they simultaneously admit are true and relevant, conceptualizing this behavior as a potential source of misinformation and distortion. The third essay investigates moral neutrality, documenting people’s discomfort with sharing controversial moral opinions, but also their distrust of others who try to avoid moral issues. Drawing on experimental methods from psychology and behavioral economics, these three essays show not only that people use strategic omission strategies to protect their moral reputation and avoid morally-charged conversations, but also that such strategies frequently come with ironic costs for social discourse, for their reputations, or for the greater good
Essays on Macroeconomics
No full textThis dissertation consists of two chapters. In the first chapter, we propose a protocol of repeated bargaining where occasional periods of increased outside opportunities yield improved outcomes but also higher breakout probabilities, yet there is a lot of risk sharing. Crucially, we only look at the Markov perfect equilibria which dispenses us from both having non payoff relevant state variables that are costly to compute nor contrived process of equilibrium selection. Using the negotiation protocol proposed in the first chapter, I study the welfare-maximizing income tax progressivity when married couples file jointly as is the U.S. income tax system. To see how progressive income tax impacts household formation and intra-household allocations, I construct a life-cycle model to study how changes in tax policy affect labor supply --- especially those of secondary earners in married households --- and household formation/dissolution. Married households make allocation decisions jointly without being able to commit future arrangements. With this model, I find the sensitivity of the marriage patterns to the tax code: changing tax unit from a household to an individual increases the number of married households by 3\%, mainly via a reduction of the marriage age coming from reduced rewards to search for advantageous tax partners. I also consider the same policy reform but abstracting the responses of marriage/divorce decisions and intra-household sharing rules to show how those are quantitatively important. We then use the model to compute the optimal income tax progressivity that maximizes welfare under two scenarios; (i) married couples filing jointly and (ii) individual taxation. In Scenario (i), the optimal progressivity for married couples is lower. At the same time, that of singles is slightly higher than the current U.S. tax code. In comparison, the optimal progressivity in Scenario (ii) is much higher than the current U.S. single income tax schedule
Penn Library\u27s Ms. Codex 1670 - Flambeau des vrais rosecroix ou des sages. (Video Orientation)
No full texthttps://repository.upenn.edu/sims_video/1147/thumbnail.jp
Collation Model for Ms. Codex 1177: [Rule of the Heilig-Geist-Spital in Eichstätt]
Get PDFCopy of the rule (Regel) of the Heilig-Geist-Spital (Hospital of the Holy Spirit) in Eichstätt, issued by Heinrich, Bishop of Eichstätt (Wir Heinrich von gotes genaden pischof ze Eysten, f. 1v), probably the last of four bishops by that name who held office between 1225 and 1259, namely Heinrich IV (1247-1259); the other possible authors are Heinrich I (1225-1228), Heinrich II (1228-1232), and Heinrich III (1233-1237). The rule governed the way of life of the monastic community (Bruderschaft, f. 7v) of priests, brothers and sisters who ran the hospital, and was evidently issued by the bishop at the request of a preexisting group (f. 1v). It is modeled on the rule of the Heilig-Geist-Orden (Order of the Holy Spirit) for the care of the sick founded by Guido von Montpellier around 1195, although it was independent of that order; and it is indirectly related to the rules of the Brothers Hospitallers of St. John of God and of St. Augustine (Bauch). The statutes address such aspects as manner of accepting new members, including required vows (chastity, poverty and obedience, as well as service to the sick); hierarchy and responsibilities of members, with a male and a female leader of brothers and sisters, respectively (Maister, Maisterin; f. 8r); dress; manner of taking in and caring for the sick; handling of income and property; accommodation of guests; customs of eating and drinking; care of sick members; punishments for offenses; confession; guidelines for pious living (Wie man geislich sul werden, f. 10r; Ain gut Lere, f. 10v); and manner of accepting lay people as affiliated members (known as a Third Order; Dritter Orden, Tertiarenbruderschaft). The manuscript contains numerous corrections in the same hand. An addendum, which is written in a different hand and dated either 1335 or 1435 (f. 1r), concerns the conditions for members receiving a sinecure or living (Pfründe, f. 1r). The manuscript is a sewn booklet, with gatherings detached from each other.https://repository.upenn.edu/sims_models/1044/thumbnail.jp
CO\u3csub\u3e2\u3c/sub\u3e and CH\u3csub\u3e4\u3c/sub\u3e to Liquids Via Low-Thermal Plasma
Get PDFThis process uses a low-thermal plasma reactor to convert carbon dioxide, natural gas, and water vapor into acetic acid, waste liquid, and flue gas. The plant requires co-location with a corn ethanol plant for carbon dioxide feed and for the disposal of liquid waste (made primarily of ethanol and methanol) as an ethanol additive. The acetic acid is the target liquid product for this process. The flue gas has significant energy value and may also be sold. In the best case scenario, the plant achieves a 33.78% internal rate of return with a $27,000,000 net present value. Other worse case scenarios are analyzed with the least favorable resulting in a 13.3%-16.8% internal rate of return
Collation Model for LJS 25: Liber metaphisice ; Liber ethicorum.
Get PDFAristotle\u27s Metaphysics and Nicomachean ethics, in the Latin translations by the Dominican William of Moerbeke from the Greek, followed by the first page of the Oeconomica, a work commonly attributed to Aristotle, in the Latin translation known as the translatio Durandi, attributed to Durand of Auvergne. The Aristotle texts are preceded by a table of contents for the Nicomachean ethics. The outer bifolium of the first gathering (before f. 1 and after f. 10), containing the beginning of the Metaphysics, a gathering after f. 22, and two leaves after f. 72 are all lacking. Many early marginal notes, some affected by cropping, and occasional manicules.https://repository.upenn.edu/sims_models/1072/thumbnail.jp