O objetivo geral desta pesquisa foi avaliar o impacto da restrição ao crédito rural sobre a produtividade da terra e a produtividade do trabalho para os agricultores familiares do Brasil. Para estimar esse impacto, foram utilizados os dados do Censo Agropecuário de 2006 por município. Para diferenciar os diferentes agricultores familiares, foi utilizado o índice de mercantilização, separando a população em quartis. As estimativas do impacto da restrição ao crédito sobre a produtividade da terra e a produtividade do trabalho foram calculadas a partir da comparação entre o grupo que recebeu crédito e o que não recebeu crédito, obtido através do escore de propensão (propensity score matching). As estimativas do efeito médio de tratamento sobre os tratados, quando apresentaram resultados estatisticamente significativos, evidenciaram os diferentes grupos formados dentro da agricultura familiar. Por exemplo, na região Centro-oeste municípios com crédito tiveram maior produtividade da terra e do trabalho quando pertencentes ao quarto quartil. Os resultados obtidos no modelo estimado mostram que os efeitos da restrição ao crédito rural são diferentes para municípios mais ou menos mercantilizados e, portanto, requerem políticas distintas. / The overall objective of this research is to evaluate the impact of the restriction of rural credit on land and labor productivity for family farmers in Brazil. In order to estimate this impact, we have used data from Brazil\'s 2006 Agricultural Census at the municipal level. To differentiate among family farmers, a trade index was used, separating the population into quartiles. Estimates of the impact of credit restriction on the productivity of land and the productivity of labor were calculated through propensity score matching. Estimates of the average treatment effect on the treated, when presenting statistically significant results, highlight the differences among groups formed within the family farm. For example, in the Midwest of Brazil, municipalities with credit and belonging to the fourth quartile presented higher land and labor productivity. The results of the estimated model confirm that the effects of rural credit restriction are different for municipalities with smaller or larger trade indices, requiring therefore specific policies for each group.

Thesis advisor: Henry I. Braun / City Connects is a school-based model that identifies the strengths and needs of every student and links each child to a tailored set of intervention, prevention, and enrichment services in the school or community. The purpose of this study was to conduct a comprehensive evaluation of the City Connects treatment effects on academic performance (both MCAS scores and grade point average (GPA) grades) in middle school using student longitudinal records. Parallel analyses were conducted: one evaluated the City Connects elementary intervention (serving kindergarten to fifth grades) and the other one evaluated the City Connects middle school intervention (serving sixth to eighth grades). A series of two-level hierarchical linear models with middle school achievement scores adjusted and/or propensity score weights applied were used to answer the research questions of interest. In addition, to make a causal inference, a sensitivity analysis was conducted to examine whether or not the estimated treatment effects resulted from the first two analyses were robust to the presence of unobserved selection bias. The results showed that students who were exposed to the City Connects elementary intervention significantly outperformed their counterparts, who graduated from the comparison elementary schools, on academic achievement in all middle school grades. However, in the case of the City Connects intervention schools that served middle school grades, since all students only received a maximum of one year of City Connects middle school intervention, it was still too soon to expect any significant changes. Moreover, the estimated treatment effects of the City Connects elementary intervention were only mildly sensitive to the presence of some forms of hidden bias, which made the causal inference of City Connects on middle school academic achievement quite plausible. / Thesis (PhD) — Boston College, 2015. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Research, Measurement and Evaluation.

O objetivo dessa dissertação é avaliar o impacto de um programa de treinamento voltado para trabalhadores, utilizando o propensity score matching, mas com dois tipos de abordagem, uma não-paramétrica e a outra semi-paramétrica. Para estimação não paramétrica foi utilizado um método proposto por Li, Racine e Wooldridge (2009) e para estimação semi-paramétrica, o modelo utilizado foi o Generalized Additive Model proposto por Hastie e Tibshirani (1990). Os resultados obtidos indicam que os dois métodos utilizados apresentam estimativas tão boas ou melhores do que quando estimadas paramétricamente. / The goal of this thesis is to evaluate the impact of a job training program using propensity score matching methods with two types of approaches: a nonparametric e another semiparametric. For non-parametric estimation was used a method proposed by Li, Racine and Wooldridge (2009) and for the semiparametric model the Generalized Additive Model proposed by Hastie and Tibshirani (1990). The results indicate that both methods provide estimates as good or better than when parametrically estimated.

Submitted by PPG Economia do desenvolvimento (economia-pg@pucrs.br) on 2018-10-19T21:27:53Z No. of bitstreams: 1 BLANCA_LILA_GAMARRA _MOREL_TES.pdf: 4056778 bytes, checksum: c115258b7c6a31660496964e5ea4548e (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-10-22T13:12:26Z (GMT) No. of bitstreams: 1 BLANCA_LILA_GAMARRA _MOREL_TES.pdf: 4056778 bytes, checksum: c115258b7c6a31660496964e5ea4548e (MD5) / Made available in DSpace on 2018-10-22T13:18:58Z (GMT). No. of bitstreams: 1 BLANCA_LILA_GAMARRA _MOREL_TES.pdf: 4056778 bytes, checksum: c115258b7c6a31660496964e5ea4548e (MD5) Previous issue date: 2018-08-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The main objective of the thesis is to analyze the level of quality of life between the coastal and non-coastal municipalities of Brazil associated to the environmental, economic and social dimensions. The specific objectives are: to characterize the socioeconomic structure of coastal and non-coastal municipalities and to identify whether there are differences in the quality of life of the population. For that, the approach of human development and economic geography was used as a theoretical reference in order to define quality of life and well-being, as well as the economic and social characteristics that are related to these concepts. The use of this theoretical framework allowed to reach a better definition of the dimensions of analysis and to proceed to the empirical analysis using the Propensity Score Matching (PSM) method. The aim was to identify differences in the quality of life between the coastal and non-coastal areas of Brazil. The empirical analysis suggests evidence contrary to the common sense that in regions with greater potential for concentration of economic activities there is a higher quality of life. Regarding the economic characteristics, the results found corroborate the theory, showing that, in fact, there is a flagrant economic concentration in the coastal municipalities. However, the analysis of environmental and social characteristics showed that although coastal municipalities are more developed from a purely economic point of view, when considered other aspects of development these municipalities perform worse. / O objetivo principal da tese ? analisar o n?vel de qualidade de vida entre os munic?pios costeiros e n?o costeiros do Brasil associado ?s dimens?es ambiental, econ?mica e social. Os objetivos espec?ficos constituem-se em: caracterizar a estrutura s?cio econ?mica dos munic?pios costeiros e n?o costeiros e identificar se existem diferenciais de qualidade de vida da popula??o. Para tanto, foram utilizados como referencial te?rico a abordagem do desenvolvimento humano e Geografia Econ?mica de modo a definir qualidade de vida e bem-estar, bem como as caracter?sticas econ?micas e sociais que est?o relacionadas com esses conceitos. A utiliza??o desse referencial te?rico permitiu alcan?ar tamb?m uma melhor defini??o das dimens?es de an?lise para, a partir de ent?o, proceder ? an?lise emp?rica utilizando-se o m?todo Propensity Score Matching (PSM). Buscou-se, assim, identificar as diferen?as de qualidade de vida entre a zona costeira e n?o costeira brasileira. A an?lise emp?rica realizada sugere evid?ncias contr?rias ao senso comum de que em regi?es com maior potencial de concentra??o de atividades econ?micas h? maior qualidade de vida. No que diz respeito ?s caracter?sticas econ?micas, os resultados encontrados corroboram a teoria, mostrando que existe, de fato, flagrante concentra??o econ?mica nos munic?pios costeiros. No entanto, a an?lise das caracter?sticas ambientais e sociais mostraram que embora os munic?pios costeiros sejam mais desenvolvidos do ponto de vista puramente econ?mico, quando considerados outros aspectos do desenvolvimento esses munic?pios apresentam desempenho pior.

Cystic fibrosis (CF) is the most common life-restricting, genetically inherited disease among Caucasians affecting approximately 30,000 people in the United States. Lung disease is the major cause of morbidity and mortality in CF. A number of oral, inhaled, and intravenous therapies are available to combat CF lung disease. Of these, this research project focused on inhaled dornase alfa, oral azithromycin, inhaled tobramycin, and inhaled aztreonam. Data to address three research aims were requested and obtained from the Cystic Fibrosis Foundation Patient Registry (CFFPR). The first aim examined the use of inhaled dornase alfa in younger children with CF. With no clinical efficacy data of dornase alfa in children ≤ 6 years of age, the study utilized subsequent forced expiratory volume in 1 second (FEV₁) measured between 6 - 7 years of age, to assess the effectiveness of long-term dornase alfa use ≤ 6 years of age. Propensity score methods were used to reduce the likelihood of treatment indication bias. The results suggested that receiving treatment with dornase alfa before 6 years of age did not improve FEV₁ between 6 - 7 years. Unmeasured covariates leading to treatment indication bias were likely one of the key explanations for these results. Additionally, lack of a more sensitive outcome than FEV₁ to assess lung function in young patients with early lung damage was thought to be another reason for the failure to reject the null hypothesis. The second aim assessed the long-term clinical effectiveness of chronic azithromycin use on the rate of FEV₁ decline in CF patients between 6 - 20 years of age. This study was novel in that the rate of FEV₁ decline, rather than change in FEV₁ from baseline, was the primary outcome, which was characterized using propensity score matching followed by a linear mixed model analysis. The results of the analysis suggested that the rate of FEV₁ decline was slower in patients who did not receive chronic treatment with azithromycin. Treatment indication bias was thought to play an important role in the direction of the association between treatment and outcome. Associations between FEV₁ % predicted and many of the other study variables included in the analysis were consistent with previous studies. The final aim compared the clinical effectiveness of a combination of inhaled tobramycin and aztreonam with inhaled tobramycin alone on the rate of FEV₁ decline in CF patients between 6 - 20 years of age. This aim was novel in that the effect of this combination treatment on rate of decline in FEV₁ has never been assessed. A linear mixed model analysis was used after matching patients in the two treatment groups on their propensity scores. Once again, the results were contrary to the alternative hypothesis with the combination group having a steeper rate of FEV₁ decline than the group that was treated with tobramycin alone. An important reason for this result was thought to be unresolved treatment indication bias that could not be eliminated even with the use of the propensity score methods used to test the associated hypothesis. The use of validated methods of analysis, i.e., propensity scores, to counter treatment indication bias using the largest available observational dataset for CF, was one of the key strengths of this study. Moreover, this study highlighted important weaknesses in the CFFPR with regards to lack of data on patient and physician-level variables - an area of active interest for the Cystic Fibrosis Foundation.

Background: Among patients with multiple chronic conditions, care coordination and integration remains one of the major challenges facing the U.S. health care system. A home-based, patient-centered primary care program has been offered through the Veterans Health Administration (VHA) since the 1970s for frail veterans who have difficulty accessing VHA clinics. The VHA Home Based Primary Care (VHA HBPC) aims to integrate primary care, rehabilitation, disease management, palliative care, and coordination of care for frail individuals with complex, chronic diseases within their homes. Early research suggested that VHA HBPC was associated with positive outcomes (e.g., reduced resource use and patient satisfaction). However, evidence regarding the effect of the VHA HBPC program on health services use (especially hospital and nursing home use), expenditures, and other patient outcomes remains limited. The present study is designed to fill this gap as the rise in the number of veterans with complex health care needs will likely increase in the coming decades. Objectives: The current study aimed to examine the impact of VHA HBPC on health services use, expenditures, and mortality among a cohort of new VHA HBPC enrollees identified in the national VHA data system. The specific aims of this study were: 1) to examine the effect of VHA HBPC on major health service use (hospital, nursing home, and outpatient care) paid for by the Veterans Administration; 2) to examine the effect of VHA HBPC on total health services expenditures; and 3) to examine whether VHA HBPC enrollees experienced similar mortality and survival as compared to a matched concurrent cohort. Methods: This study used a retrospective cohort design. A new VHA HBPC enrollee cohort (the treatment group) and a propensity matched comparison cohort (the comparison group) were identified from VHA claims in fiscal years (FY) 2009 and 2010 and were followed through FY 2012. Data on health service use, expenditures, and mortality/survival data were obtained via the VHA administrative datasets (i.e., Decision Support System, Purchased Care, and Vital Status Files). Propensity scores of being enrolled in the VHA HBPC were generated by a logistic regression model controlling for potential confounders. After 41,244 matched pairs were determined adequate through several diagnostic methods, means tests, relative risk analyses, and generalized linear models were used to estimate the effect of VHA HBPC on outcomes. Additionally, a Cox proportional hazards regression model was used to estimate the effect of VHA HBPC on survival. Subgroup analyses were conducted stratifying by age (85 and older), comorbidities (2 or more), and the receipt of palliative care. Based on the results of the original analyses, a series of sensitivity analyses were conducted that modified the described sample selection criteria and matching algorithm. Results: Analyses of the original cohort revealed that VHA HBPC patients had significantly higher risks of being admitted into a hospital (RR 1.53, 95% CI 1.51-1.56) or nursing home (RR 1.65, CI 1.50 - 1.81). The average total expenditures during the study period were significantly higher for the VHA HBPC group as compared to the control group ($85,808 vs. $44,833, respectively; p < .001). In terms of mortality and survival, VHA HBPC enrollees had higher mortality (RR 1.45, CI 1.43 - 1.47), and shorter survival (HR 1.89, CI 1.86 - 1.93) as compared to those in the comparison group. Subgroup analyses found that these relationships generally remained when stratified by age 85 or older or having two or more comorbidities. However, for those who received palliative care, VHA HBPC participants had significantly lower risk of VHA hospitalization overall (RR 0.84, CI 0.81 - 0.87) and immediately prior to death. Finally, exploratory post-hoc analysis suggested that VHA HBPC recipients were at higher risk of VHA hospitalization at 30 (RR 1.11, CI 1.06 - 1.16), 60 (RR 1.16, CI 1.11 - 1.20), and 90 days (RR 1.16, 1.12 - 1.21) prior to death relative to the comparison group. After selecting only those that had a baseline hospitalization and refining the matching algorithm to account for time to death and additional comorbidities, VHA HBPC participants who had been enrolled in the program for at least six months had lower risks for hospital (RR 0.89, CI 0.88 - 0.90) and nursing home admissions (RR 0.74, CI 0.67 - 0.81). However, total expenditures remained significantly higher among those in VHA HBPC relative to the comparison group ($89,761 vs. $85,371, respectively; p < .001). Discussion: This study found that without accounting for important covariates such as initial hospitalization, time to death, and a range of comorbidities, VHA HBPC was associated with higher health service use, higher expenditures, higher mortality, and shorter survival as compared to a similar group of patients not receiving VHA HBPC. After accounting for these factors, VHA HBPC was associated with a lower risk of nursing home use, and after six months, VHA HBPC was associated with lower risk of both nursing home and hospital use. These findings suggest that while VHA HBPC may improve quality of life and patient satisfaction through patient-centered integrated primary care, it may not generate cost savings for the healthcare system. Future research is needed to understand variation in program implementation and how this affects the impact of VHA HBPC on service use and cost.

<p>This thesis consists of three papers that examine college choice and earnings among university graduates in Sweden.</p><p>Paper [I] analyzes how geographical accessibility to higher education affects university enrollment decisions in Sweden. The empirical findings show that the probability of enrollment in university education increases with accessibility to university education. The results also indicate that accessibility adds to the likelihood of attending a university within the region of residence. Both these findings are robust with regard to different specifications of accessibility. The empirical results furthermore indicate that the enrollment decisions of individuals with a less privileged background are more sensitive to accessibility to university education than are the decisions of individuals from a more favorable background.</p><p>Paper [II] examines the effect on earnings of graduating from five different college groups. The paper relies on selection on observables and linear regression to identify the earnings effect of college choice. Contrary to the majority of previous Swedish studies, we do not find any systematic differences in estimated earnings between college graduates from the different college groups. This finding does not only hold when considering all college graduates, but also when focusing on men and women separately as well as when considering college graduates in two specific fields of education. The results suggest that an estimator of the earnings effects of college choice that does not properly adjust for ability is likely to be substantially biased.</p><p>Paper [III] estimates the causal effect on earnings of graduating from old universities rather than new universities/university colleges. The study compares estimates from several different matching methods and linear regression. We cannot find any significant differences in earnings between graduates from the two groups of colleges. This holds for male and female sub-samples covering all majors, as well as male and female sub-samples covering two broad fields of education. The results are robust with regard to different methods of propensity score matching and regression adjustment. Furthermore, the results indicate little sensitivity with regard to the empirical support in the data and alternative specifications of the propensity scores.</p>

<p>In this paper I study how the repeal of the Swedish wealth tax (1 of January 2007) has affected people´s labour supply behaviour. This particular issue is relevant because it may help us understand some of the effects of the earnings tax changes that have taken place in Sweden. Accoring to standard economic theory a repealed wealth tax is similar to an income effect for the persons who previously paid the tax. That means that they theoretically will want to consume more leisure, that is decrease their labour supply. The method I am using to test this hypothesis is a difference-in-difference approach where the treatment group consists of persons who previously paid the tax and the control group of comparable persons who did not pay the tax. The data I am using is taken from a Swedish database called LINDA, compiled by the Swedish Central Agency for Statistics (SCB). My main result in this paper is that the repealed wealth tax does not seem to have had any influnece on the labour supply behavior of the persons who previously paid the tax.</p>

<p>Using data from the Labour Force Survey conducted by Statistics South Africa twice yearly this thesis intend to evaluate the Expanded Public Works Programme regarding its effectiveness in creating employment and raising income in households with participating individuals. The South African labour market is well known for its high rates of unemployment and also its segregation, primarily between black and white people, but also young people are having a hard time finding jobs. In order to fight these problems the South African government has launched the Expanded Public Works Programme(EPWP) which provides low- semi-skilled labour with short term employment, the primary target groups being black and coloured people, women, disabled people and young people. Our findings indicate that the EPWP does not significantly enhance the individual’s probability of being employed, nor does it raise the per capita income of households with participating individuals.</p>

This thesis consists of three papers that examine college choice and earnings among university graduates in Sweden. Paper [I] analyzes how geographical accessibility to higher education affects university enrollment decisions in Sweden. The empirical findings show that the probability of enrollment in university education increases with accessibility to university education. The results also indicate that accessibility adds to the likelihood of attending a university within the region of residence. Both these findings are robust with regard to different specifications of accessibility. The empirical results furthermore indicate that the enrollment decisions of individuals with a less privileged background are more sensitive to accessibility to university education than are the decisions of individuals from a more favorable background. Paper [II] examines the effect on earnings of graduating from five different college groups. The paper relies on selection on observables and linear regression to identify the earnings effect of college choice. Contrary to the majority of previous Swedish studies, we do not find any systematic differences in estimated earnings between college graduates from the different college groups. This finding does not only hold when considering all college graduates, but also when focusing on men and women separately as well as when considering college graduates in two specific fields of education. The results suggest that an estimator of the earnings effects of college choice that does not properly adjust for ability is likely to be substantially biased. Paper [III] estimates the causal effect on earnings of graduating from old universities rather than new universities/university colleges. The study compares estimates from several different matching methods and linear regression. We cannot find any significant differences in earnings between graduates from the two groups of colleges. This holds for male and female sub-samples covering all majors, as well as male and female sub-samples covering two broad fields of education. The results are robust with regard to different methods of propensity score matching and regression adjustment. Furthermore, the results indicate little sensitivity with regard to the empirical support in the data and alternative specifications of the propensity scores.