Reassessing the Demography Hypothesis: the Great Brazilian Crime Shift

Mimicking the US in 1980 and 1990s, Brazil is a remarkable case of a major shift in homicides. After increasing steadily throughout the 1990s and the beginning of the 2000s, homicides reached a peak in 2003, and then fell. I show a strong time-series co-movement between homicide rates and the percentage of the population in 15-24 age bracket. Using a panel of states, I find a very high elasticity of homicide with respect to changes in the 15-24 year-old population (2.4), after controlling for income, income inequality, and state and year fixed effects. I then focus on the case of São Paulo, the largest state in the country, and whose shift in homicides has been particularly acute. City-level panel elasticities are similar to the state-level estimates. Furthermore, the demographic shift in São Paulo was more pronounced than the national one, explaining the particularly large shift in homicides in São Paulo. The large cohort born from the mid 1970 through the early 1980 is the result of a sharp reduction in infant mortality only belatedly followed by acceleration in the reduction of fertility. In line with the Easterlin Hypothesis (Easterlin [1980]), this large cohort faced tough economic conditions. Educational attainment ceased to improve for this cohort, and unemployment rates upon entering the job market were exceptionally high. Thus, the large homicide shift in Brazil is produced by a particularly large and socially fragile cohort.Age Structure, Demographic Change, Homicides

Costly horizontal differentiation

We study the effect of quadratic differentiation costs in the Hotelling model of endogenous product differentiation. The equilibrium location choices are found to depend on the magnitude of the differentiation costs (relatively to the transportation costs supported by consumers). When the differentiation costs are low, there is maximum differentiation. When they are intermediate, there is partial differentiation, with a degree of differentiation that decreases with the differentiation costs. When they are above a certain threshold, there is no equilibrium. In any case, the socially optimal degree of differentiation is always lower than the equilibrium level. We also study the case of collusion between firms. If firms can combine locations but not prices, they locate asymmetrically when differentiation costs are high and choose maximum differentiation when they are low. When collusion extends to price setting, there is partial differentiation.Costly product differentiation, Spatial competition, Hotelling model

A relational theory of relationship lending under contractual incompleteness

While the literature has focused on relationships as a technology for solving hidden information problems in credit markets, hidden action has been very little explored as an explanation for the existence of relational lending. In this paper, we propose a theory in which relationships are driven by the problem of contractual incompleteness in instances in which a borrower, by taking ex-ante actions, magnifies the hazards related to ex-post bargaining over returns. A relationship commits the borrower to take actions that minimize the ex-post conflict of interests resulting from contractual incompleteness. We show that a robust feature of an optimally designed lending relationship (i.e., the best Public Perfect Pure Strategy Equilibrium in a repeated lending game) is that a sufficiently patient entrepreneur, upon choosing his actions, ignores his privately observed contingencies. This commitment solves the credit rationing problem that arises in a one-shot (arm’s length) interaction, and reduces, when compared to arm’s length financing, the interest rate that a bank charges for a credit line. Although in a less acute fashion, we also show that the same features just described appear in an optimal lending relationship for the case in which the entrepreneur is impatient.

Relationship lending: Is it Incentives or hidden information?

Relationships are a valuable technology to produce loans. (Berger and Udell [1995], Petersen and Rajan [1994], Aoki and Dinç [2002]). While there are convincing theories in which relationships solve hidden action or hidden information problems, there is very little empirical corroboration of either theory. In this paper, we assess the empirically validity of these theories in the small firm credit market. While results suggest that relationships are more valuable for firms with worse incentive misaligment problems, more informationally opaque firms do not seem to extract more value from relationships. Contrary to what most empirical research on the value of relationships has assumed (but not tested), this indicates that relationships are, at very least, as important for aligning incentives as they are for solving hidden information problems.

Does crime affect economic decisions? An empirical investigation of savings in a high-crime environment

While most economic studies of crime have focused on its determinants, we study the reverse question: does crime affect economic behavior? Being such an important social phenomenon, one would expect crime to affect economic decisions. Using local data on crime rates and savings per capita in a high-crime environment, we document a striking empirical relationship: crime induces savings. Our paper is one of the first to successfully relate crime to an economic outcome. This result is robust to an extensive sensitivity analysis, which include: 1) controlling to a large set of demographic covariates; 2) accounting for the fact that crime and savings may be determined jointly; 3) measuring savings in different ways; 4) accounting for the presence of possible outliers; 5) weighting the data according to population; 6) accounting for spatial correlation; and, finally, 7) estimating the model for different sub-samples of cities. Our estimates indicate that only property, not violent, crime induces savings, which is consistent with the theoretical explanations on why crime would increase thriftinessCrime, Economic Behavior, Savings

Age Structure Explaining a Large Shift in Homicides: The Case of the State of São Paulo

After reaching a historic peak by the end of the 1990s, homicides in large cities in the state of São Paulo dropped sharply. Several explanations have been advanced, most prominently improvements in policing, adoption of policies such as dry laws, and increased incarceration. In this paper, we show that demographic changes play a large role in explaining the dynamics of homicide. More specifically, we present evidence of a strong co-movement between the proportion of males on the 15-25 age bracket and homicides at the statewide and at city levels, and argue that the relationship is causal. We estimate that a 1% increase in the proportion of 15-to-24-year-old males causes a 4.5% increase in homicides.Age Structure, Demographic Change, Homicides

Influence of the human head in the radiation of a mobile antenna

The big proliferation of mobile communication systems has caused an increased concern about the interaction between the human body and the antennas of mobile handsets. In order to study the problem, a multiband antenna was designed, fabricated and measured to operate over two frequency sub bands 900 and 1800 MHz. After that, we simulated the same antenna, but now, in the presence of a human head model to analyze the head's influence. First, the influence of the human head on the radiation efficiency of the antenna has been investigated as a function of the distance between the head and the antenna and with the inclination of the antenna. Furthermore, the relative amount of the electromagnetic power absorbed in the head has been obtained. In this study the electromagnetic analysis has been performed via FDTD (Finite Difference Time Domain)

Saúde e distress psicológico em pessoas com 80 e mais anos residentes na comunidade

Mestrado em GerontologiaIntrodução: O grupo de pessoas com 80 e mais anos é o segmento populacional que mais cresce anualmente e espera-se que até 2050 constitua 3,4% do total da população mundial (UN, 2002). Com o avançar da idade, perdas relacionadas com o processo de envelhecimento traduzem-se numa pior saúde física e funcional, mas são precisamente as pessoas mais velhas, com 80 e mais anos, que avaliam a sua saúde como mais positiva, especialmente quando se compararam com outras pessoas. Este paradoxo constitui uma das grandes contradições da literatura que foca as especificidades do grupo dos muito velhos e sugere a influência de outros factores na mediação entre saúde objectiva e subjectiva. Objectivo: Este estudo pretende descrever e comparar o estado socioeconómico e indicadores de saúde em três grupos etários (65-68, 70-79 e 80+ anos) e analisar a dinâmica da relação entre as três componentes da saúde consideradas – objectiva (saúde física e funcional), subjectiva (auto-percepção de saúde) e mental (distress psicológico) na idade avançada. Metodologia: Recorreu-se a uma amostra de 991 pessoas residentes na comunidade, 698 mulheres (70.4%), com idades compreendidas entre os 65 anos e os 101 anos (média de 74.1 anos, SD 6.5). Na recolha de dados utilizou-se o General Health Questionnaire (GHQ-12; Goldberg and Blackwell, 1970) e o Questionário sobre Saúde e Estilos de Vida (Paúl et al., 1999 - adaptado). Foi também recolhida informação sociodemográfica. Resultados: Análises comparativas entre os grupos etários demonstraram diferenças significativas na saúde subjectiva, objectiva e mental dos indivíduos. O grupo das pessoas muito idosas (n= 207) revelou pior saúde objectiva, com mais pessoas a apresentar incapacidade (AVD e AIVD) e pior capacidade de visão, e uma melhor auto-percepção de saúde (quando se comparam a outras pessoas). A prevalência de distress psicológico na amostra total foi de 26.8%, verificando-se um aumento significativo com a idade. Nos modelos de regressão logística a interacção entre o distress psicológico e a saúde subjectiva mostrou ser estatisticamente significativa. As pessoas sem distress psicológico, apesar das dificuldades funcionais e da condição física, percebem a sua saúde como melhor. Conclusões: A heterogeneidade do grupo das “pessoas idosas” e o perfil daquelas com 80 e mais anos devem ser reconhecidos, nomeadamente em estudos gerontológicos, no desenho de políticas e no desenvolvimento de intervenções clínicas. Independentemente da saúde física, existem outros factores que influenciam a forma como as pessoas idosas e muito idosas auto-avaliam a sua saúde, nomeadamente a saúde mental, pelo que devem ser desenvolvidas estratégias que visem a promoção do bem-estar psicológico a par da promoção da saúde física.Introduction: People aged 80 years and over are the segment of the population that grows faster, and it is expected that by the year 2050 this group will represent 3.4% of the total population of the world (UN, 2002). With advancing age, despite disability and age-related losses, some people succeed in evaluating their health more positively, especially when comparing with others. This paradox is one of the biggest contradictions in the literature that focus the very-old and suggests the existence of moderating influences in the relation between objective and subjective health. Aims: This study aims to describe and compare the socioeconomic status and the health indicators in three age groups (65-68, 70-79 and 80+ years old) and analyze the relation between objective health (physical and functional status), subjective health (self-perception of health) and mental health (psychological distress) in advanced old age. Methods: The sample consists of 991 community-dwelling participants, 698 women (70.4%), with ages between 65 and 101 years (mean age 74.1, SD 6.5). The General Health Questionnaire (GHQ-12; Goldberg and Blackwell, 1970) and the Questionnaire on Health and Lifestyles (Paúl et al., 1999 - adapted) were used for collecting data. Socio-demographic information was also collected. Results: Comparative analyses showed significant differences in subjective, objective and mental health among age groups. The older group (n= 207) was more likely to have worse objective health, with greater levels of disability (ADL and IADL) and more vision difficulties, and a better subjective health (when compared to others). The prevalence of psychological distress on the total sample was of 26.8%, with and increased prevalence with age. In the regression model analysis, the interaction between psychological distress and subjective health was found to be significant. Persons without psychological distress, despite functional difficulties or physical conditions, perceived their health as better than people with psychological distress. Conclusions: The heterogeneity of “old people” group and the old-old profile should be recognized in the gerontological studies, for the definition of policies and the development of clinical interventions. Besides physical health, there are other factors that contribute way old and very old-people evaluated their health, namely the presence of psychological distress. Strategies that focus on the promotion of psychological well-being should complement the ones aiming to promote physical health