Influence of Weapon Types on the Patterns and Outcomes of Violent Encounters

Rapport de stage présenté à l'école de Criminologie de la Faculté des arts et sciences en vue de l'obtention du grade de Maître ès sciences (M.Sc.) en criminologie option analyse criminologique

Empowering IDP with SMS: a randomized controlled trial in Bogotá

We carried out a randomized controlled trial in Bogotá, the recipient of Colombia´s highest number of internally displaced people (IDP), to assess whether the use of SMS to communicate eligibility to social benefits fosters the welfare of victimized internal refugees. Only a fraction of IDP are elegible to benefits. We inform eligibility via SMS to a random half of IDP-households who are, and estimate the Local Average Treatment Effect of the text message on the knowledge of the benefits available tothe displaced population. We show that while on the average treated households know their rights better than controls, a more disaggregate analysis suggest that there is variation of awareness across benefits. The intervention was overall successful in empowering IDP and the use of SMS should be widened as a social policy instrument. However our results suggest that text messages should be complemented with other communication strategies, yet to be evaluated.

Employment Protection Legislation and Firm Growth : Evidence from a Natural Experiment

A natural experiment is used to identify the causal relationship between employment protection legislation and fi…rm growth. The natural experiment occurred in Sweden in 2001, when an exemption made it possible for fi…rms with less than eleven employees to exclude two workers from the last-in-fi…rst-out principle when dismissing personnel. The estimated average treatment effect of the reform show that the number of employees increased with 0.135 percent in fi…rms with 5-9 employees relative to fi…rms with 10-15 employees, which corresponds to over 5,000 additional jobs per year created by the reform. Firms with ten employees, just below the size threshold, became 3.4 percent less likely to increase their workforce to a level surpassing the threshold, indicating that the last-in-…first-out rule prevented these …firms from growing. Thus, employment protection legislation seems to act as a growth barrier for small fi…rms.

The Olympic impact on hosting candidate countries

In this paper, we analyze the impact of hosting the Summer Olympics on macroeconomic aggregates such as GDP, consumption, government consumption and investments per capita. The data is in panel structure and includes the period of ten years before and ten years after the event containing the Olympic Summer Games between 1960 and 1996. The sample countries comprise only candidates to host the games. This sampling strategy allows us to estimate the average treatment effect consistently, because it is assumed that these countries are comparable to each other, including those that ultimately hosted the games. The impact of hosting the Olympic games is measured by Fixed Effect and First Difference regressions. Moreover, we do a structural break test developed by Andrews (1993) to identify if hosting the Olympic Games creates anticipation effects for demand changes that stimulate current GDP, consumption, government consumption and investments. The results indicate a positive effect of the Summer Olympics in all variables of interest. However, the distribution in time and anticipation of these effects is unclear in the tests, changing significantly depending on the model and the significance level used.

Clinical effectiveness of cognitive behavioral therapy for depression in routine care: A propensity score based comparison between randomized controlled trials and clinical practice

Background: The efficacy of cognitive behavioral therapy (CBT) for the treatment of depressive disorders has been demonstrated in many randomized controlled trials (RCTs). This study investigated whether for CBT similar effects can be expected under routine care conditions when the patients are comparable to those examined in RCTs. Method: N=574 CBT patients from an outpatient clinic were stepwise matched to the patients undergoing CBT in the National Institute of Mental Health Treatment of Depression Collaborative Research Program (TDCRP). First, the exclusion criteria of the RCT were applied to the naturalistic sample of the outpatient clinic. Second, propensity score matching (PSM) was used to adjust the remaining naturalistic sample on the basis of baseline covariate distributions. Matched samples were then compared regarding treatment effects using effect sizes, average treatment effect on the treated (ATT) and recovery rates. Results: CBT in the adjusted naturalistic subsample was as effective as in the RCT. However, treatments lasted significantly longer under routine care conditions. Limitations: The samples included only a limited amount of common predictor variables and stemmed from different countries. There might be additional covariates, which could potentially further improve the matching between the samples. Conclusions: CBT for depression in clinical practice might be equally effective as manual-based treatments in RCTs when they are applied to comparable patients. The fact that similar effects under routine conditions were reached with more sessions, however, points to the potential to optimize treatments in clinical practice with respect to their efficiency.

Bounding ATE with ITT

We propose the bounds on ATE using intention-to-treat (ITT) estimator when there are compliers/noncompliers in randomized trials. The bounds are given as ITTaverage treatment effect (CACE) can be computed from ITT and complier ratio. We show that these bounds can be derived from two assumptions: (1) average treatment effect is greater with compliers than noncompliers or CACE>NACE, (2) noncompliers' average treatment effect (NACE) is nonnegative. We give an example of poverty impacts of health insurance, and effects of adverse selection and moral hazard of health insurance.

Avaliação de impacto do Proagro Mais: um estudo de caso

Esta pesquisa avalia o impacto do \"Programa de Garantia da Atividade Agropecuária\" para agricultores familiares, conhecido como Proagro Mais. A relevância do trabalho fundamenta-se no considerável tamanho do Programa dentro do contexto das políticas de gestão de risco agrícola no Brasil. Além disso, é a primeira pesquisa desse tipo na literatura científica do país. A amostra é formada por produtores de milho do Estado do Paraná, tendo como linha base o ano de 2003, uma vez que é o ano anterior ao lançamento do Proagro Mais, e o ano de 2005 como ano de impacto. A base de dados utilizada neste estudo foi fornecida pelo Tribunal de Contas da União (TCU), cujas variáveis relevantes incluem características da cultura e dos agricultores familiares, como área financiada, atividades agrícolas complementares, educação e rendimento esperado. Adicionalmente, a partir de outras fontes públicas, foram adicionadas variáveis meteorológicas e regionais para controlar a localização da fazenda. O objetivo da pesquisa é avaliar o impacto do Proagro Mais sobre o montante de crédito por hectare concedido aos beneficiários do Programa. As metodologias usadas incluem o Propensity Score Matching (PSM), a Diferença das Diferenças (DID) e dois estimadores condicionais do DID com PSM usando dados em painel e repeated cross-section. As estimativas econométricas mostram que o Efeito Médio do Tratamento nos Tratados (EMTT) teve sinal negativo na maioria dos modelos revelando que, após o período de perda de rendimento, o grupo de controle teve um valor médio mais elevado de crédito por hectare do que os beneficiários do Proagro Mais. Os resultados sugerem a existência de mecanismos que poderiam complementar ou substituir o Proagro Mais como instrumento de gestão de risco agrícola, mas também podem sugerir que o Programa avaliado não cubra todos os riscos do setor.

Essays on Microeconometrics

My dissertation has three chapters which develop and apply microeconometric tech- niques to empirically relevant problems. All the chapters examines the robustness issues (e.g., measurement error and model misspecification) in the econometric anal- ysis. The first chapter studies the identifying power of an instrumental variable in the nonparametric heterogeneous treatment effect framework when a binary treat- ment variable is mismeasured and endogenous. I characterize the sharp identified set for the local average treatment effect under the following two assumptions: (1) the exclusion restriction of an instrument and (2) deterministic monotonicity of the true treatment variable in the instrument. The identification strategy allows for general measurement error. Notably, (i) the measurement error is nonclassical, (ii) it can be endogenous, and (iii) no assumptions are imposed on the marginal distribution of the measurement error, so that I do not need to assume the accuracy of the measure- ment. Based on the partial identification result, I provide a consistent confidence interval for the local average treatment effect with uniformly valid size control. I also show that the identification strategy can incorporate repeated measurements to narrow the identified set, even if the repeated measurements themselves are endoge- nous. Using the the National Longitudinal Study of the High School Class of 1972, I demonstrate that my new methodology can produce nontrivial bounds for the return to college attendance when attendance is mismeasured and endogenous.

The second chapter, which is a part of a coauthored project with Federico Bugni, considers the problem of inference in dynamic discrete choice problems when the structural model is locally misspecified. We consider two popular classes of estimators for dynamic discrete choice models: K-step maximum likelihood estimators (K-ML) and K-step minimum distance estimators (K-MD), where K denotes the number of policy iterations employed in the estimation problem. These estimator classes include popular estimators such as Rust (1987)’s nested fixed point estimator, Hotz and Miller (1993)’s conditional choice probability estimator, Aguirregabiria and Mira (2002)’s nested algorithm estimator, and Pesendorfer and Schmidt-Dengler (2008)’s least squares estimator. We derive and compare the asymptotic distributions of K- ML and K-MD estimators when the model is arbitrarily locally misspecified and we obtain three main results. In the absence of misspecification, Aguirregabiria and Mira (2002) show that all K-ML estimators are asymptotically equivalent regardless of the choice of K. Our first result shows that this finding extends to a locally misspecified model, regardless of the degree of local misspecification. As a second result, we show that an analogous result holds for all K-MD estimators, i.e., all K- MD estimator are asymptotically equivalent regardless of the choice of K. Our third and final result is to compare K-MD and K-ML estimators in terms of asymptotic mean squared error. Under local misspecification, the optimally weighted K-MD estimator depends on the unknown asymptotic bias and is no longer feasible. In turn, feasible K-MD estimators could have an asymptotic mean squared error that is higher or lower than that of the K-ML estimators. To demonstrate the relevance of our asymptotic analysis, we illustrate our findings using in a simulation exercise based on a misspecified version of Rust (1987) bus engine problem.

The last chapter investigates the causal effect of the Omnibus Budget Reconcil- iation Act of 1993, which caused the biggest change to the EITC in its history, on unemployment and labor force participation among single mothers. Unemployment and labor force participation are difficult to define for a few reasons, for example, be- cause of marginally attached workers. Instead of searching for the unique definition for each of these two concepts, this chapter bounds unemployment and labor force participation by observable variables and, as a result, considers various competing definitions of these two concepts simultaneously. This bounding strategy leads to partial identification of the treatment effect. The inference results depend on the construction of the bounds, but they imply positive effect on labor force participa- tion and negligible effect on unemployment. The results imply that the difference- in-difference result based on the BLS definition of unemployment can be misleading

due to misclassification of unemployment.

Economic Evaluations of State Policies

Thesis (Ph.D.)--University of Washington, 2016-08

Effect of cold plasma treatment on mechanical properties of PET/PMMA composites

Mechanical strength of polyethylene terephthalate (PET) fibres and polymethyl methacrylate (PMMA) matrix composites were studied with particular interest on the effects of oxygen and argon plasma treated fibres. PET. fibres were treated in a radio frequency plasma reactor using argon or oxygen for different treatment times to increase the interface adhesion. Fibre volume fraction was measured through digital image analysis. Elastic moduli resulted between 3 GPa for untreated to 6 GPa for treated composites. Tensile tests on PET fibres showed that plasma treatment caused a decrease in average tensile strength compared to untreated fibres. Fracture analysis confirmed the increase in interfacial adhesion due to plasma treatment. (c) 2004 Elsevier Ltd. All rights reserved.

Conditional treatment and its effect on recidivism

The objective of this paper is to evaluate the effect of the 1985 ”Employment Services for Ex-Offenders” (ESEO) program on recidivism. Initially, the sample has been split randomly in a control group and a treatment group. However, the actual treatment (mainly being job related counseling) only takes place conditional on finding a job, and not having been arrested, for those selected in the treatment group. We use a multiple proportional hazard model with unobserved heterogeneity for job seach and recidivism time which incorporates the conditional treatment effect. We find that the program helps to reduce criminal activity, contrary to the result of the previous analysis of this data set. This finding is important for crime prevention policy.

Lighting and violent crimes: evaluating the effect of an electrification policy in rural Brazil on violent crime reduction

This paper estimates the effect of lighting on violent crime reduction. We explore an electrification program (LUZ PARA TODOS or Light for All - LPT) adopted by the federal government to expand electrification to rural areas in all Brazilian municipalities in the 2000s as an exogenous source of variation in electrification expansion. Our instrumental variable results show a reduction in homicide rates (approximately five homicides per 100,000 inhabitants) on rural roads/urban streets when a municipality moved from no access to full coverage of electricity between 2000 and 2010. These findings are even more significant in the northern and northeastern regions of Brazil, where rates of electrification are lower than those of the rest of the country and, thus, where the program is concentrated. In the north (northeast), the number of violent deaths on the streets per 100,000 inhabitants decreased by 48.12 (13.43). This moved a municipality at the 99th percentile (75th) to the median (zero) of the crime distribution of municipalities. Finally, we do not find effects on violent deaths in households and at other locations. Because we use an IV strategy by exploring the LPT program eligibility criteria, we can interpret the results as the estimated impact of the program on those experiencing an increase in electricity coverage due to their program eligibility. Thus, the results represent local average treatment effects of lighting on homicides.

Effect of intravaginal electrical stimulation on pelvic floor muscle strength

The aim of this study was to evaluate the effect of intravaginal electrical stimulation (IES) on pelvic floor muscle (PFM) strength in patients with mixed urinary incontinence (MUI). Between January 2001 and February 2002, 40 MUI women (mean age: 48 years) were studied. Urge incontinence was the predominant symptom; 92.5% also presented mild stress urinary incontinence (SUI). Selection criteria were clinical history and urodynamics. Pre-treatment urodynamic study showed no statistical differences between the groups. Ten percent of the women in each group had involuntary detrusor contractions. Patients were randomly distributed, in a double-blind study, into two groups. Group G 1 (n=20), effective IES, and group G2 (n=20), sham IES, with follow-up at 1 month. The following parameters were studied: (1) clinical questionnaire, (2) examiner's evaluation of perineal muscle strength, (3) objective evaluation of perineal muscle by perineometry, (4) vaginal weight test, and (5) urodynamic study. The IES protocol consisted of three 20-min sessions per week over a 7-week period using a Dualpex Uro 996 at 4 Hz. There was no statistically significant difference in the demographic data of both groups. The number of micturitions per 24 h after treatment was reduced significantly in both groups. Urge incontinence, present in all patients before treatment, was reduced to 15% in G1 and 31.5% in G2 post-treatment. The subjective evaluation of PFM strength demonstrated a significant improvement in G1. Objective evaluation of PFM force by perineometer showed a significant improvement in maximum peak contraction post-treatment in both groups. In the vaginal weight test, there was a significant increase in average number of cone retentions post-treatment in both groups. With regard to satisfaction level, after treatment, 80% of the patients in G1 and 65% of the patients in G2 were satisfied. There was no statistically significant difference between the groups. There was a significant improvement in PFM strength from both effective and sham electrostimulation, questioning the effectiveness of electrostimulation as a monotherapy in treating MUI.

Effect of monomer treatment and polymerisation methods on the bond strength of resin teeth to denture base material

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of ridge lap surface treatment and thermocycling on microtensile bond strength of acrylic teeth to denture base resins

This study evaluated the effect of denture base polymer type (heat- and microwave-polymerized), ridge lap surface treatment (with and without methyl methacrylate-MMA etching) and thermocycling on the microtensile bond strength (mTBS) of Biotone acrylic teeth. Flat-ground, ridge-lap surface of posterior artifcial teeth were bonded to cylinders of each denture base resin, resulting in the following groups (n=6): G1a - Clássico/with MMA etching; G1b - Clássico/without MMA etching; G2a - OndaCryl/with MMA etching; G2b - OndaCryl/without MMA etching. Rectangular bar specimens with a cross-sectional area of 1 mm 2 were prepared. Half of the bars in each group were thermocycled (5,000 cycles between 4°C and 60°C). mTBS testing was performed in an universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed statistically by three-way ANOVA (a=0.05). There was no statisti-caly signifcant difference (p>0.05) for the factors (resin, surface treatment,and thermocycling) or their interactions. The mean mTBS values (MPa) and standard deviations were as follows: Thermocycling - G1a: 41.00 (14.00); G1b: 31.00 (17.00); G2a: 50.00 (27.00); G2b: 40.00 (18.00); No thermocycling - G1a: 37.00 (14.00); G1b: 43.00 (25.00); G2a: 43.00 (14.00); G2b: 40.00 (27.00). The mTBS of Biotone artifcial teeth to the denture base acrylic resins was not infuenced by the polymer type, surface treatment or thermocycling.