Essays On Human Capital And Altruism

This dissertation contains three self-contained chapters on human capital and altruism. The first two chapters explore why women used to lag behind but now exceed men in college enrollment. Chapter 1 shows that examining occupations that require only a high school degree ( non-college occupations) can help resolve two puzzles. First, why do women attend college at greater rates than men today, when men work more and earn more than women? I document that non-college occupations for men are both more plentiful and higher paying than those for women. Next, I link the occupational inequality in the non-college labor market to the gap in college enrollment, by employing two empirical exercises to show that non-college jobs dramatically affect college-going decisions. Using employment changes in the oil and gas industry, I demonstrate that increases in men\u27s non-college job opportunities lead male high school graduates to forego college enrollment. Using the automation of the office, I demonstrate that declines in the non-college employment opportunities of women lead female college enrollment to grow over time. Thus, women\u27s lower non-college job prospects contribute to their higher college enrollment. This leads to the second puzzle: why did women initially attend college at lower rates than men, when women have always had worse non-college job prospects than men? I develop a theoretical model to demonstrate that both the importance and availability of non-college occupations for women contributed to women\u27s initially low enrollment, as well as to the growth in female enrollment over time, such that women eventually overtook men in college-going. Chapter 1 argues that gender differences in occupations, particularly in the non-college labor market, lead women to choose to attend college at greater rates than men. In Chapter 2, I explore one key mechanism behind the severe occupational segregation in the non-college labor market. Using data from the National Longitudinal Study of Youth (1979), I show that there exist large differences in skill profiles between men and women. In particular, gender-based skill for men tends to represent mechanical skill, while gender-based skill for women tends to represent numerical and coding ability. Using a Roy model adapted from Rosen and Willis (1979), I show that gender-based skill for men commands a return in the non-college labor market and therefore increases the opportunity cost of college attendance. Gender-based skill for women, on the other hand, does not appear to increase women\u27s non-college earnings. Finally, I find that these skill differences significantly impact the likelihood of enrolling in college through their effect on wages. By increasing the value of the outside option to attending college for men, gender-based skill contributes to the greater college enrollment rate of women. Chapter 3, joint with Judd Kessler and Katherine Milkman, explores altruism in a unique field context. We examine how reciprocity, an important motivation behind altruism, changes over time using a large quasi-experiment in the field. Specifically, we analyze administrative data from a university hospital system. The data include information about over 18,000 donation requests made by the hospital system via mail to a set of its former patients in the four months following their first hospital visit. We exploit quasi-experimental variation in the timing of solicitation mailings relative to patient hospital visits and find that an extra 30-day delay between the provision of medical care and a donation solicitation decreases the likelihood of a donation by 30%. Our findings have important implications for models of economic behavior, which currently fail to incorporate reciprocity\u27s sensitivity to time. The fact that reciprocal behavior decays rapidly as time passes also suggests the importance of capitalizing quickly on opportunities to benefit from a quid pro quo

\u27Feel the Warmth\u27 Glow: A Field Experiment on Manipulating the Act of Giving

We conducted a field experiment with a charitable group to investigate whether giving the donor an option to write a personalized holiday card to the recipient influences giving behavior. Over 1500 households were approached in a door-to-door campaign and randomized to either a treatment group, in which donors were presented with the option to write their own card for the recipient, or a control group, in which donors were not given the option to write their own card for the recipient. We predict that treatment should increase contributions through making the gift more meaningful, but may also decrease contributions by increasing the transaction and social costs of donating. We find evidence in favor of the negative effects of costs from treatment, and no evidence of increased giving. We also observe that our treatment crowds out small donors (donors giving $5 or less)

The effects of daily chlorhexidine bathing on cutaneous bacterial isolates: a pilot study

Chlorhexidine gluconate (CHG) is a topical antiseptic used in a myriad of clinical settings. Recently, CHG baths have been shown to decrease multidrug-resistant organism acquisition and infections and catheter-associated bloodstream infections. The present study examined the effects of daily bathing with CHG on the recovery and antimicrobial susceptibility of cultivable cutaneous bacteria. The objectives of this study were to (1) explore the effects of clinical CHG bathing on cultivable cutaneous bacteria, (2) study the relationship between CHG minimum inhibitory concentration and antimicrobial susceptibility of coagulase-negative staphylococci, and (3) demonstrate the feasibility of the approach so a more definitive study may be performed. Significant decreases in bacterial colony counts and phenotypic diversity occurred with greater CHG exposure. The findings also suggest an inverse relationship between CHG minimum inhibitory concentration and antimicrobial susceptibility. Larger prospective studies are necessary to fully investigate the clinical impact of CHG usage

Previous antibiotic exposure increases risk of infection with extended-spectrum-β-lactamase- and AmpC-producing Escherichia coli and Klebsiella pneumoniae in pediatric patients

The objective of this study was to determine whether antibiotic exposure is associated with extended-spectrum-beta-lactamase- or AmpC-producing Escherichia coli or Klebsiella pneumoniae infections in children. We collected extended-spectrum-beta-lactamase- or AmpC-producing E. coli or K. pneumoniae isolates and same-species susceptible controls from normally sterile sites of patients aged ≤21 years, along with associated clinical data, at four free-standing pediatric centers. After controlling for potential confounders, the relative risk of having an extended-spectrum-beta-lactamase-producing isolate rather than a susceptible isolate was 2.2 times higher (95% confidence interval [CI], 1.49 to 3.35) among those with antibiotic exposure in the 30 days prior to infection than in those with no antibiotic exposure. The results were similar when analyses were limited to exposure to third-generation cephalosporins, other broad-spectrum beta-lactams, or trimethoprim-sulfamethoxazole. Conversely, the relative risk of having an AmpC-producing versus a susceptible isolate was not significantly elevated with any antibiotic exposure in the 30 days prior to infection (adjusted relative risk ratio, 1.12; 95% CI, 0.65 to 1.91). However, when examining subgroups of antibiotics, the relative risk of having an AmpC-producing isolate was higher for patients with exposure to third-generation cephalosporins (adjusted relative risk ratio, 4.48; 95% CI, 1.75 to 11.43). Dose-response relationships between antibiotic exposure and extended-spectrum-beta-lactamase-producing or AmpC-producing isolates were not demonstrated. These results reinforce the need to study and implement pediatric antimicrobial stewardship strategies, and they indicate that epidemiological studies of third-generation cephalosporin-resistant E. coli and K. pneumoniae isolates should include resistance mechanisms when possible

Apoplast proteome reveals that extracellular matrix contributes to multistress response in poplar

<p>Abstract</p> <p>Background</p> <p>Riverine ecosystems, highly sensitive to climate change and human activities, are characterized by rapid environmental change to fluctuating water levels and siltation, causing stress on their biological components. We have little understanding of mechanisms by which riverine plant species have developed adaptive strategies to cope with stress in dynamic environments while maintaining growth and development.</p> <p>Results</p> <p>We report that poplar (<it>Populus </it>spp.) has evolved a systems level "stress proteome" in the leaf-stem-root apoplast continuum to counter biotic and abiotic factors. To obtain apoplast proteins from <it>P. deltoides</it>, we developed pressure-chamber and water-displacement methods for leaves and stems, respectively. Analyses of 303 proteins and corresponding transcripts coupled with controlled experiments and bioinformatics demonstrate that poplar depends on constitutive and inducible factors to deal with water, pathogen, and oxidative stress. However, each apoplast possessed a unique set of proteins, indicating that response to stress is partly compartmentalized. Apoplast proteins that are involved in glycolysis, fermentation, and catabolism of sucrose and starch appear to enable poplar to grow normally under water stress. Pathogenesis-related proteins mediating water and pathogen stress in apoplast were particularly abundant and effective in suppressing growth of the most prevalent poplar pathogen <it>Melampsora</it>. Unexpectedly, we found diverse peroxidases that appear to be involved in stress-induced cell wall modification in apoplast, particularly during the growing season. Poplar developed a robust antioxidative system to buffer oxidation in stem apoplast.</p> <p>Conclusion</p> <p>These findings suggest that multistress response in the apoplast constitutes an important adaptive trait for poplar to inhabit dynamic environments and is also a potential mechanism in other riverine plant species.</p

Test of variables of attention (TOVA) as a predictor of early attention complaints, an antecedent to dementia

The goal of this study was to determine if impairments detected by the test of variables of attention (TOVA) may be used to predict early attention complaints and memory impairments accurately in a clinical setting. We performed a statistical analysis of outcomes in a patient population screened for attention deficit hyperactivity disorder or attention complaints, processing errors as measured by TOVA and the Wechsler Memory Scale (WMS-III) results. Attention deficit disorder (ADD) checklists, constructed using the Diagnostic and Statistical Manual of Mental Disorders 4th Edition criteria, which were completed by patients at PATH Medical, revealed that 72.8% of the patients had more than one attention complaint out of a total of 16 complaints, and 41.5% had more than five complaints. For the 128 males with a significant number of ADD complaints, individuals whose scores were significantly deviant or borderline (SDB) on TOVA, had a significantly greater number of attention complaints compared with normals for omissions (P < 0.02), response time (P < 0.015), and variability (P < 0.005), but not commissions (P > 0.50). For males, the mean scores for auditory, visual, immediate, and working memory scores as measured by the WMS-III were significantly greater for normals versus SDBs on the TOVA subtest, ie, omission (P < 0.01) and response time (P < 0.05), but not variability or commissions. The means for auditory, visual, and immediate memory scores were significantly greater for normals versus SDBs for variability (P < 0.045) only. In females, the mean scores for visual and working memory scores were significantly greater for normals versus SDBs for omissions (P < 0.025). The number of SDB TOVA quarters was a significant predictor for “impaired” or “normal” group membership for visual memory (P < 0.015), but not for the other three WMS-III components. For males, the partial correlation between the number of attention complaints and the number of SDB TOVA quarters was also significant (r = 0.251, P < 0.005). For the 152 females with a significant number of attention complaints, no significant differences between SDBs and normals were observed (P > 0.15). This is the first report, to our knowledge, which provides evidence that TOVA is an accurate predictor of early attention complaints and memory impairments in a clinical setting. This finding is more robust for males than for females between the ages of 40 and 90 years

Skunk River Review September 1993, vol 5

https://openspace.dmacc.edu/skunkriver/1008/thumbnail.jp