Covariate quality has been primarily theory driven in propensity score matching with a general adversity to the interpretation of group prediction. However, effect sizes are well supported in the literature and may help to inform the method. Specifically, I index can be used as a measure of effect size in logistic regression to evaluate group prediction. As such, simulation was used to create 35 conditions of I, initial bias and sample size to examine statistical differences in (a) post-matching bias reduction and (b) treatment effect sensitivity. The results of this study suggest these conditions do not explain statistical differences in percent bias reduction of treatment likelihood after matching. However, I and sample size do explain statistical differences in treatment effect sensitivity. Treatment effect sensitivity was lower when sample sizes and I increased. However, this relationship was mitigated within smaller sample sizes as I increased above I = .50.

A presente dissertação visa avaliar, a partir do uso dos dados da Pesquisa de Atividade Econômica Paulista - PAEP - do ano de 1996, da RAIS - Relação Anual de Informações Sociais de 1992, 1993, 1997 e 1998 e da SECEX - Secretaria do Comércio Exterior - dos anos de 1992 e 1993, a relação entre a atividade de inovação tecnológica e os potenciais impactos produzidos sobre o nível de emprego e sobre o nível de renda na indústria paulista entre os anos de 1997 e 1998. Como a inovação não é um evento aleatório, há o viés de seleção da amostra, de tal sorte que uma comparação direta entre os efeitos da inovação sobre certas variáveis daquelas firmas que inovaram com aquelas que não inovaram, na situação de ter havido inovação, produziria vieses. Tal problema é resolvido neste trabalho por meio do Propensity Score Matching, que visa o pareamento de unidades tratamento - controle para a obtenção dos resultados intentados, a saber, a variação na renda e no nível de emprego. Ademais, de modo a inibir a presença de efeitos não observáveis, recorre-se ao método de Diferenças em Diferenças (DID). Os resultados obtidos atestam para um aumento, na média, do nível de emprego para quase todos os tipos de atividade inovativa empreendidas. Em contrapartida, os achados se revelaram estatisticamente insignificantes para a variação de renda, também em quase todos os tipos de inovação. / This work intends to analyze, by the usage of three different data sources, PAEP (1996), RAIS - Relação Anual de Informações Sociais (1992, 1993, 1997, and 1998) and SECEX - Secretaria do Comércio Exterior (from 1992, and 1993) the relationship, if that exists, between innovation and its potential impacts over employment level as well as salaries during the 1997 - 1998 period. Once innovation activity cannot be considered as a random event, we incur in the well known selection bias problem. Consequently, a direct comparison of the innovation impacts between those firms which effectively innovated with those which did not innovate would be misleading. Such a problem may be corrected with the Propensity Score Matching, which consists in the establishment of treatment - control pairs in order to obtain the results previously searched. Moreover, in an attempt to control for the unobserved effects, it is applied the Differences in Differences Methodology (DID). Results obtained show that, on the one hand, for almost all the innovation activities considered, there was an increment in the level of employment. On the other hand, for most of the cases, there were not statistically significant results for an impact of innovation activities on the level of salaries.

Neste trabalho analisou-se o impacto das remessas financeiras sobre os patrimônios dos ativos nos domicílios, no país de origem. Utilizamos dados da Encuesta Permanente de Hogares de 2008, os quais foram fornecidos pelo órgão Dirección General de Estadística, Encuestas y Censos do Paraguai. Com estes dados realizamos uma comparação entre os domicílios com e sem remessas, independente de terem ou não emigrantes. A metodologia utilizada para realizar a comparação foi o Propensity Score Matching (PSM) com dois algoritmos, Vizinhos Próximos e Kernel. Os patrimônios dos ativos são carros, aluguéis e combinados. Os resultados em todos os casos foram estatisticamente significativos, porém, negativos. Com amesma metodologia e os mesmos dados, comparamos apenas os domicílios com emigrantes, e os resultados continuaram negativos, porém, com nível de significância menor. / In this study we analyzed the impact of remittances on financial assets in the wealth of households in the country of origin. We use data from the Encuesta Permanente Hogares 2008, which were provided by the agency Dirección General de Estadística, Encuestas y Censos of Paraguay. With these data we performed a comparison between households with and without remittances, regardless of whether or not immigrants. The methodology for conducting the comparison was the Propensity Score Matching (PSM) with two algorithms, Kernel and Nearest Neighbors. The stockholders\' assets are cars, rentals and combined. The results in all cases were statistically significant, but negative. With the same methodology and same data, comparing only households with migrants, the results remained negative, but with lower significance level.

Neste trabalho analisou-se o impacto das remessas financeiras sobre os patrimônios dos ativos nos domicílios, no país de origem. Utilizamos dados da Encuesta Permanente de Hogares de 2008, os quais foram fornecidos pelo órgão Dirección General de Estadística, Encuestas y Censos do Paraguai. Com estes dados realizamos uma comparação entre os domicílios com e sem remessas, independente de terem ou não emigrantes. A metodologia utilizada para realizar a comparação foi o Propensity Score Matching (PSM) com dois algoritmos, Vizinhos Próximos e Kernel. Os patrimônios dos ativos são carros, aluguéis e combinados. Os resultados em todos os casos foram estatisticamente significativos, porém, negativos. Com amesma metodologia e os mesmos dados, comparamos apenas os domicílios com emigrantes, e os resultados continuaram negativos, porém, com nível de significância menor. / In this study we analyzed the impact of remittances on financial assets in the wealth of households in the country of origin. We use data from the Encuesta Permanente Hogares 2008, which were provided by the agency Dirección General de Estadística, Encuestas y Censos of Paraguay. With these data we performed a comparison between households with and without remittances, regardless of whether or not immigrants. The methodology for conducting the comparison was the Propensity Score Matching (PSM) with two algorithms, Kernel and Nearest Neighbors. The stockholders\' assets are cars, rentals and combined. The results in all cases were statistically significant, but negative. With the same methodology and same data, comparing only households with migrants, the results remained negative, but with lower significance level.

A presente dissertação visa avaliar, a partir do uso dos dados da Pesquisa de Atividade Econômica Paulista - PAEP - do ano de 1996, da RAIS - Relação Anual de Informações Sociais de 1992, 1993, 1997 e 1998 e da SECEX - Secretaria do Comércio Exterior - dos anos de 1992 e 1993, a relação entre a atividade de inovação tecnológica e os potenciais impactos produzidos sobre o nível de emprego e sobre o nível de renda na indústria paulista entre os anos de 1997 e 1998. Como a inovação não é um evento aleatório, há o viés de seleção da amostra, de tal sorte que uma comparação direta entre os efeitos da inovação sobre certas variáveis daquelas firmas que inovaram com aquelas que não inovaram, na situação de ter havido inovação, produziria vieses. Tal problema é resolvido neste trabalho por meio do Propensity Score Matching, que visa o pareamento de unidades tratamento - controle para a obtenção dos resultados intentados, a saber, a variação na renda e no nível de emprego. Ademais, de modo a inibir a presença de efeitos não observáveis, recorre-se ao método de Diferenças em Diferenças (DID). Os resultados obtidos atestam para um aumento, na média, do nível de emprego para quase todos os tipos de atividade inovativa empreendidas. Em contrapartida, os achados se revelaram estatisticamente insignificantes para a variação de renda, também em quase todos os tipos de inovação. / This work intends to analyze, by the usage of three different data sources, PAEP (1996), RAIS - Relação Anual de Informações Sociais (1992, 1993, 1997, and 1998) and SECEX - Secretaria do Comércio Exterior (from 1992, and 1993) the relationship, if that exists, between innovation and its potential impacts over employment level as well as salaries during the 1997 - 1998 period. Once innovation activity cannot be considered as a random event, we incur in the well known selection bias problem. Consequently, a direct comparison of the innovation impacts between those firms which effectively innovated with those which did not innovate would be misleading. Such a problem may be corrected with the Propensity Score Matching, which consists in the establishment of treatment - control pairs in order to obtain the results previously searched. Moreover, in an attempt to control for the unobserved effects, it is applied the Differences in Differences Methodology (DID). Results obtained show that, on the one hand, for almost all the innovation activities considered, there was an increment in the level of employment. On the other hand, for most of the cases, there were not statistically significant results for an impact of innovation activities on the level of salaries.

This thesis addresses to what extent childhood family composition – the number of siblings and whether the parents live together, or whether there are non-parental adults and/or half-siblings in the household or not – contributes to variations in adult earnings. The theoretical perspective suggests that resources mediate the effect. While research has shown that siblings, as well as divorce and remarriage, are negatively linked to child outcomes, there are inconsistencies in previous literature. There has been debate over the unconfoundedness of previous studies, something that is handled here by analyzing large sets of representative data using a robust parameter. The longitudinal dataset used is based on Swedish administrative data and the cohorts analyzed are born in the beginning of the 1970s. The data structure is well suited for the assumptions underlying the semi-parametric method propensity score matching. The findings show that family size impacts on adult earnings. However, this is not always of concern. For example, no effect of siblings is found in affluent families, and if siblings are closely spaced this results in better outcomes for children. Divorce and remarriage do not seem to lower the future earnings of children. Thus, this thesis shows that some of the most well-established patterns in the sociology of the family, namely the link between number of siblings and adult earnings, and between divorce/family re-formation and adult earnings, can be broken by resources.

The purpose of this study was to explore the relationship of dual enrollment course participation by comparing first-time, full-time traditional community college students who participated in dual enrollment (N=246) to peers (N=986) that did not participate. Dual enrollment participation was defined as taking one or more dual enrollment courses. The population for this study (N=1,232) included first-time, full-time students who graduated from public high schools in the service area of Northeast State Community College over a five year span from 2008 through 2012. Propensity score matching eliminated self-selection bias by controlling for confounding covariates such as parental education, high school GPA, and ACT scores. The major findings of the study included the following: dual enrollment participants (a) were nearly four times less likely to take remediation than non-participants, (b) earned approximately 1 extra credit hour in the first semesters of college, (c) earned higher first semester GPAs, (d) were 2.5 times more likely to graduate in 2 years (100% of degree time) and, (e) were 1.68 times more likely to graduate in 3 years (150% of degree time). The study concluded that dual enrollment benefits community college students in Tennessee, both at the beginning and completion of college. This is a significant justification for the current investment in dual enrollment by the State of Tennessee and for further increasing access to dual enrollment for all students, especially for students that live in rural areas, experience poverty, or are underrepresented in higher education.

<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>

This thesis examines determinants of the adoption of total mixed ration (TMR), and the effects of the adoption of TMR on the farm level productivity and profitability of Ontario dairy farms. A sample of 320 farm level data from 2004-2008 is taken from the Ontario Dairy Farm Accounting Project (ODFAP). A probit model is estimated to examine the factors affecting the adoption of TMR; and the propensity score matching analysis is used to explore the influence of the use of TMR on sample farm’s productivity and profitability. Results from the probit model show that farmer’s age, herd size, region, breed type and feeding system have significant effect on the adoption of TMR. In turn, the adoption of TMR feeding practice has positive influence on both farm productivity and profitability. Under the propensity score matching method, the use of the TMR feeding practice has an economically significant effect on farm profits (i.e., for average farm with approximately 73 cows, the use of TMR feeding practice increases farm profits by CAD$37,091.30/year approximately) and a statistically significant increase in milk production by 1075.41 hl/cow per year.

Objective: The study assesses the impact of dual enrollment participation on remediation and completion for traditional first time, full-time freshmen at a community college in Northeast Tennessee. Method: This study began with the full population of 1,232 students who enrolled between 2008 and 2012 at a community college in northeast Tennessee the fall semester after finishing high school. The population was required to have American College Testing (ACT) scores, completely fill out the Free Application for Federal Student Aid (FAFSA), enroll full-time as a degree-seeking student, and complete the first fall semester. Propensity score matching was utilized to eliminate self-selection bias and enable parametric comparisons using optimal matching of dual enrollment participants and non-participants while controlling for a range of covariates. Results: The analyses showed that community college students who participated in dual enrollment were (a) 9% or nearly 3.4 times less likely to take remediation, (b) 26% or nearly 2.5 times more likely to graduate in 2 years, and (c) 28% or nearly 1.5 times more likely to graduate in 3 years. Contributions: This study contributes to the literature showing that dual enrollment reduces remediation rates and assists in timely completions for community college students. Policy recommendations are to increase equitable participation, normalize dual enrollment for students academically able to do college coursework, align state terminology with the nation, and improve data for future research.