Three essays analyzing the role of social capital on individual and firm decision making

The following dissertation is comprised of three essays that focus on different mechanisms on which social capital influences firm and entrepreneur behavior. All three essays use different econometric techniques to account for endogenous variables. Essay 1: Are Local Market Relationships Trumping Organic Certification? The Case of Small and Medium Fruit and Vegetable Farmers. This article investigates how an organic fruit and vegetable farmer’s choice to use direct-to-consumer market channels impacts his/her decision to be certified organic. First, we model the decision to be certified organic as a conditionally independent decision from the farmer’s chosen market channels. Second, we estimate the probability of certifying organic as an endogenously determined marketing decision to the choice of market channels, and use a bivariate probit specification to model this decision. Empirical evidence indicates that the decision to certify is endogenous to the chosen market channels. We show that farmers selling direct to consumers are less likely to certify organic. Essay 2: The Economic Implications of Social Capital on Hispanic Entrepreneurship. This essay assesses the effect of social capital, defined as the clustering of Hispanics, on the probability of Hispanic business creation. A big issue in xii the social capital literature is identification. We use new econometric procedures to try to address this possible endogeneity and draw causal conclusions on the effect of social interactions on individual economic behavior. This essay provides robust empirical evidence on the role of social capital on Hispanic entrepreneurship. We also tackle the constructs of Hispanic heterogeneity and find that second generation Hispanics may be used as a potential indicator for Hispanic entrepreneurial environment. Essay 3: The Resilience of Small Business: A Post-Katrina Analysis of Social Capital. Small business resilience becomes more relevant as natural disasters become more frequent. Post-disaster business resilience is the product of many complex decisions that result from the interaction of individuals, families, businesses, and communities. Little is known about what it takes for a small business to build resilience after a natural disaster and most studies have focused at a single point in time or look at the community as the unit of analysis. This study enhances the literature by providing empirical evidence on the factors that help small businesses to build post-disaster resilience over time. This article bridges the gap between social capital and post-disaster small business resilience. We answer two main questions. Does social capital explain small business resilience after a natural disaster? And, what type of social capital has the greatest impact for building small business resilience? These questions aim to shed light on the relevance of social networks to help small businesses face post-disaster situations. Incentives and interventions should support the creation and strengthening of community linkages through community participation and leadership development

Three essays analyzing the role of social capital on individual and firm decision making

The following dissertation is comprised of three essays that focus on different mechanisms on which social capital influences firm and entrepreneur behavior. All three essays use different econometric techniques to account for endogenous variables. Essay 1: Are Local Market Relationships Trumping Organic Certification? The Case of Small and Medium Fruit and Vegetable Farmers. This article investigates how an organic fruit and vegetable farmer’s choice to use direct-to-consumer market channels impacts his/her decision to be certified organic. First, we model the decision to be certified organic as a conditionally independent decision from the farmer’s chosen market channels. Second, we estimate the probability of certifying organic as an endogenously determined marketing decision to the choice of market channels, and use a bivariate probit specification to model this decision. Empirical evidence indicates that the decision to certify is endogenous to the chosen market channels. We show that farmers selling direct to consumers are less likely to certify organic. Essay 2: The Economic Implications of Social Capital on Hispanic Entrepreneurship. This essay assesses the effect of social capital, defined as the clustering of Hispanics, on the probability of Hispanic business creation. A big issue in xii the social capital literature is identification. We use new econometric procedures to try to address this possible endogeneity and draw causal conclusions on the effect of social interactions on individual economic behavior. This essay provides robust empirical evidence on the role of social capital on Hispanic entrepreneurship. We also tackle the constructs of Hispanic heterogeneity and find that second generation Hispanics may be used as a potential indicator for Hispanic entrepreneurial environment. Essay 3: The Resilience of Small Business: A Post-Katrina Analysis of Social Capital. Small business resilience becomes more relevant as natural disasters become more frequent. Post-disaster business resilience is the product of many complex decisions that result from the interaction of individuals, families, businesses, and communities. Little is known about what it takes for a small business to build resilience after a natural disaster and most studies have focused at a single point in time or look at the community as the unit of analysis. This study enhances the literature by providing empirical evidence on the factors that help small businesses to build post-disaster resilience over time. This article bridges the gap between social capital and post-disaster small business resilience. We answer two main questions. Does social capital explain small business resilience after a natural disaster? And, what type of social capital has the greatest impact for building small business resilience? These questions aim to shed light on the relevance of social networks to help small businesses face post-disaster situations. Incentives and interventions should support the creation and strengthening of community linkages through community participation and leadership development

Risk of COVID-19 after natural infection or vaccinationResearch in context

Summary: Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health

Risk of COVID-19 after natural infection or vaccinationResearch in context

Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health