Responses to Institutional Constraints

Institutions, as mechanisms of social order, often constrain the behavior of individuals within a society. Political institutions constrain the behavior of politicians, financial institutions constrain the behavior of businesses and payment processors and social institutions often constrain the behavior of individuals. These institutions often play an important role in constraining activities that may be seen as illicit or unwanted and careful analysis of these constraints can allow researchers to learn more about activities that are often hidden or go unreported.This dissertation explores the role of institutional constraints on unwanted behavior by studying deforestation in Brazil and Malawi as well as underground activity in fraudulent software sales. These cases share the commonality that they are influenced by institutional constraints. Politicians in Brazil are constrained by reelection incentives, perpetrators of fraudulent antivirus software are constrained by payment processors and the cultural practice of ethnic favoritism in public good provision leads to particular ethnic groups in Malawi receiving much more fertilizer subsidies than others.The first chapter examines deforestation in Brazil. Local political authority (formal or informal) over natural resources may create rents for politicians. The political decision to use or allocate resources involves balancing private rents with reelection prospects. I examine the case of deforestation in Brazil and a presidential decree granting the federal government the authority to punish counties that failed to limit total deforestation within their borders. This collective punishment aimed to generate pressure on local politicians to slow deforestation. Using binding term limits as a source of variation in reelection eligibility, I find eligibility has no effect on deforestation prior to the decree. After the decree, reelection eligible mayors reduced annual deforestation 10% more than mayors ineligible for reelection. These findings are consistent with the equilibrium outcome of a lobbying model. Policies such as sanctions, which target the electorate in order to influence political behavior, may be less effective when politicians are not accountable to voters.The second chapter examines Fake antivirus (AV) programs which have been utilized to defraud millions of computer users into paying as much as one hundred dollars for a phony software license. As a result, fake AV software has evolved into one of the most lucrative criminal operations on the Internet. In this chapter, we examine the operations of three large scale fake AV businesses, lasting from three months to more than two years. More precisely, we present the results of our analysis on a trove of data obtained from several backend servers that the cybercriminals used to drive their scam operations. Our investigations reveal that these three fake AV businesses had earned a combined revenue of more than $130 million dollars. A particular focus of our analysis is on the financial and economic aspects of the scam, which involves legitimate credit card networks as well as more dubious payment processors. In particular, we present an economic model that demonstrates that fake AV companies are actively monitoring the refunds (chargebacks) that customers demand from their credit card providers. When the number of chargebacks increases in a short interval, the fake AV companies react to customer complaints by granting more refunds. This lowers the rate of chargebacks and ensures that a fake AV company can stay in business for a longer period of time. However, this behavior also leads to unusual patterns in chargebacks, which can potentially be leveraged by vigilant payment processors and credit card companies to identify and ban fraudulent firms. This chapter is joint work with Brett Stone-Gross, Richard Kremmerer, Christopher Kruegel, Douglas Steigerwald, and Giovanni Vigna and was published as Stone-Gross et al. (2013).The final chapter returns to deforestation and studies it in the context of agriculture in Malawi. The effect of development policies on the environment is often ambiguous ex ante. Programs designed to improve agricultural productivity may increase deforestation by raising the marginal productivity of agricultural land, thus increasing the demand for land clearing. However, in a setting of subsistence farming on unproductive land, increasing agricultural productivity may reduce the need to shift cultivation to maintain the desired yields. This chapter examines the impact of agricultural subsidies on deforestation in Malawi by leveraging ethnic favoritism in government resource allocation. By exploiting a change in the ethnicity of the Malawi president following the 2004 election, we show that coethnic districts received more fertilizer subsidies and experienced significant declines in deforestation compared to districts with other predominant ethnicities. This paper studies a case in which poverty alleviation programs have beneficial environ- mental impacts demonstrating that, in certain contexts, input subsidies may provide a ‘win-win’ scenario. This chapter is joint work with Conor Carney

Molecular Identification of Bacteria in Tracheal Aspirate Fluid from Mechanically Ventilated Preterm Infants

BACKGROUND: Despite strong evidence linking infections to the pathogenesis of bronchopulmonary dysplasia (BPD), limitations of bacterial culture methods have precluded systematic studies of airway organisms relative to disease outcomes. Application of molecular bacterial identification strategies may provide new insight into the role of bacterial acquisition in the airways of preterm infants at risk for BPD. METHODS: Serial (within 72 hours, 7, 14, and 21 days of life) tracheal aspirate samples were collected from 10 preterm infants with gestational age ≤34 weeks at birth, and birth weight of 500-1250 g who required mechanical ventilation for at least 21 days. Samples were analyzed by quantitative real time PCR assays for total bacterial load and by pyrosequencing for bacterial identification. RESULTS: Subjects were diagnosed with mild (1), moderate (3), or severe (5) BPD. One patient died prior to determination of disease severity. 107,487 sequences were analyzed, with mean of 3,359 (range 1,724-4,915) per sample. 2 of 10 samples collected <72 hours of life contained adequate bacterial DNA for successful sequence analysis, one of which was from a subject exposed to chorioamnionitis. All other samples exhibited bacterial loads >70copies/reaction. 72 organisms were observed in total. Seven organisms represented the dominant organism (>50% of total sequences) in 31/32 samples with positive sequences. A dominant organism represented>90% of total sequences in 13 samples. Staphylococcus, Ureaplasmaparvum, and Ureaplasmaurealyticum were the most frequently identified dominant organisms, but Pseudomonas, Enterococcus, and Escherichia were also identified. CONCLUSIONS: Early bacterial colonization with diverse species occursafter the first 3 days of life in the airways of intubated preterm infants, and can be characterized by bacterial load and marked species diversity. Molecular identification of bacteria in the lower airways of preterm infants has the potential to yield further insight into the pathogenesis of BPD

Pulmonary hemodynamic responses to in utero ventilation in very immature fetal sheep

<p>Abstract</p> <p>Background</p> <p>The onset of ventilation at birth decreases pulmonary vascular resistance (PVR) resulting in a large increase in pulmonary blood flow (PBF). As the large cross sectional area of the pulmonary vascular bed develops late in gestation, we have investigated whether the ventilation-induced increase in PBF is reduced in immature lungs.</p> <p>Methods</p> <p>Surgery was performed in fetal sheep at 105 d GA (n = 7; term ~147 d) to insert an endotracheal tube, which was connected to a neonatal ventilation circuit, and a transonic flow probe was placed around the left pulmonary artery. At 110 d GA, fetuses (n = 7) were ventilated <it>in utero </it>(IUV) for 12 hrs while continuous measurements of PBF were made, fetuses were allowed to develop <it>in utero </it>for a further 7 days following ventilation.</p> <p>Results</p> <p>PBF changes were highly variable between animals, increasing from 12.2 ± 6.6 mL/min to a maximum of 78.1 ± 23.1 mL/min in four fetuses after 10 minutes of ventilation. In the remaining three fetuses, little change in PBF was measured in response to IUV. The increases in PBF measured in responding fetuses were not sustained throughout the ventilation period and by 2 hrs of IUV had returned to pre-IUV control values.</p> <p>Discussion and conclusion</p> <p>Ventilation of very immature fetal sheep <it>in utero </it>increased PBF in 57% of fetuses but this increase was not sustained for more than 2 hrs, despite continuing ventilation. Immature lungs can increase PBF during ventilation, however, the present studies show these changes are transient and highly variable.</p

Pulmonary hypertension in infants with bronchopulmonary dysplasia

An increase in the number of preterm infants and a decrease in the gestational age at birth have resulted in an increase in the number of patients with significant bronchopulmonary dysplasia (BPD) and secondary pulmonary hypertension (PH). PH contributes significantly to the high morbidity and mortality in the BPD patients. Therefore, regular monitoring for PH by using echocardiography and B-type natriuretic peptide (BNP) or N-terminal-proBNP must be conducted in the BPD patients with greater than moderate degree to prevent PH and to ensure early treatment if PH is present. In the BPD patients with significant PH, multi-modality treatment, including treatment for correcting an underlying disease, oxygen supply, use of diverse selective pulmonary vasodilators (inhaled nitric oxide, inhaled prostacyclins, sildenafil, and endothelin-receptor antagonist) and other methods, is mandatory

Antenatal Determinants of Bronchopulmonary Dysplasia and Late Respiratory Disease in Preterm Infants

RATIONALE: Mechanisms contributing to chronic lung disease after preterm birth are incompletely understood. OBJECTIVES: To identify antenatal risk factors associated with increased risk for bronchopulmonary dysplasia (BPD) and respiratory disease during early childhood after preterm birth, we performed a prospective, longitudinal study of 587 preterm infants with gestational age less than 34 weeks and birth weights between 500 and 1,250 g. METHODS: Data collected included perinatal information and assessments during the neonatal intensive care unit admission and longitudinal follow-up by questionnaire until 2 years of age. MEASUREMENTS AND MAIN RESULTS: After adjusting for covariates, we found that maternal smoking prior to preterm birth increased the odds of having an infant with BPD by twofold (P = 0.02). Maternal smoking was associated with prolonged mechanical ventilation and respiratory support during the neonatal intensive care unit admission. Preexisting hypertension was associated with a twofold (P = 0.04) increase in odds for BPD. Lower gestational age and birth weight z-scores were associated with BPD. Preterm infants who were exposed to maternal smoking had higher rates of late respiratory disease during childhood. Twenty-two percent of infants diagnosed with BPD and 34% of preterm infants without BPD had no clinical signs of late respiratory disease during early childhood. CONCLUSIONS: We conclude that maternal smoking and hypertension increase the odds for developing BPD after preterm birth, and that maternal smoking is strongly associated with increased odds for late respiratory morbidities during early childhood. These findings suggest that in addition to the BPD diagnosis at 36 weeks, other factors modulate late respiratory outcomes during childhood. We speculate that measures to reduce maternal smoking not only will lower the risk for preterm birth but also will improve late respiratory morbidities after preterm birth

Paediatric pulmonary arterial hypertension: updates on definition, classification, diagnostics and management.

Paediatric pulmonary arterial hypertension (PAH) shares common features of adult disease, but is associated with several additional disorders and challenges that require unique approaches. This article discusses recent advances, ongoing challenges and distinct approaches for the care of children with PAH, as presented by the Paediatric Task Force of the 6th World Symposium on Pulmonary Hypertension. We provide updates of the current definition, epidemiology, classification, diagnostics and treatment of paediatric PAH, and identify critical knowledge gaps. Several features of paediatric PAH including the prominence of neonatal PAH, especially in pre-term infants with developmental lung diseases, and novel genetic causes of paediatric PAH are highlighted. The use of cardiac catheterisation as a diagnostic modality and haemodynamic definitions of PAH, including acute vasoreactivity, are addressed. Updates are provided on issues related to utility of the previous classification system to reflect paediatric-specific aetiologies and approaches to medical and interventional management of PAH, including the Potts shunt. Although a lack of clinical trial data for the use of PAH-targeted therapy persists, emerging data are improving the identification of appropriate targets for goal-oriented therapy in children. Such data will likely improve future clinical trial design to enhance outcomes in paediatric PAH