Conhecimento ou Práticas Pedagógicas? Medindo os Efeitos da Qualidade dos Professores no Desempenho dos Alunos
TD n. 620, 08/05/2014
Mauricio Fernandes, Claudio Ferraz.
Navegue nas categorias para acessar o conteúdo de publicações acadêmicas, científicas e de opinião dos professores e alunos do Departamento de Economia da PUC-Rio.
TD n. 620, 08/05/2014
Mauricio Fernandes, Claudio Ferraz.
TD n. 619, 24/04/2014
We build a theoretical model that incorporates unionization in the
labor market into a Heckscher-Ohlin-Samuelson (HOS) framework to in-
vestigate the impact of unionization on the Stolper-Samuelson Theorem.
To capture the American economy case, we assume that unskilled labor in
the manufactured goods sector is unionized, and that sector is intensive
in skilled labor, and that trade liberalization increases the relative price
of manufactured goods. In the HOS model, trade liberalization induces
a reallocation of production towards the sector that uses intensively the
country's most abundant factor. The resulting change in relative labor de-
mand impacts wage bargaining in the unionized sector, which, in turn, has
a dampening eect on the Stolper-Samuelson eect. Moreover, wages of
unionized workers are even less responsive to trade liberalization. Through
traditional mandated-wages regressions, we show that skilled-wage dier-
entials changes were less pronounced among more unionized sectors in the
U.S. economy for the 1979-1990 period.
Gustavo Gonzaga, Beatriz Cristina Muriel Hernández, Cristina Terra.
TD n. 632, 09/03/2014
This paper develops and estimates an equilibrium model where heterogeneous firms can exploit two margins of informality: (i) not register their business, the extensive margin; and (ii) hire workers "off the books", the intensive margin. The model encompasses the main competing frameworks for understanding informality and provides a natural setting to infer their empirical relevance. The counterfactual analysis shows that once the intensive margin is accounted for, aggregate firm and labor informality need not move in the same direction as a result of policy changes. Lower informality can be, but is not necessarily associated to higher GDP, TFP or welfare.
Gabriel Ulyssea.
TD n. 606, 31/01/2014
We analyze the impact of the controls and restrictions on capital inflows that Brazil has adopted since late 2009. We document that these measures had some success in segmenting the Brazilian and global financial markets, as measured by wedges between onshore and offshore prices of similar fixed and variable income assets. However, that failed to translate into significant changes in the exchange rate, at least in the immediate aftermath of these measures, suggesting limited success in mitigating real appreciation. But capital controls/restrictions may have contributed to the sizable depreciation of the real in 2012, possibly amplifying the effect on the exchange rate of cuts in the interest policy rate during that period. (revisto em 8/2014)
Marcos Chamon, Márcio Garcia.
TD n. 616, 19/09/2013
Neste artigo documentamos haver entre alunos do ensino básico no Brasil uma relação negativa e significativa entre dispersão etária dentro das turmas e a proficiência individual. A relação entre a defasagem idade-série da criança e a sua proficiência escolar é usualmente explicada por diversos fatores que influenciam o processo de formação educacional, já que tanto a defasagem idade-série de um aluno quanto a sua proficiência refletem dificuldades implícitas da vida da criança. Contudo, mostramos que essa relação negativa entre dispersão etária das turmas/classes escolares e proficiência individual pode ser mitigada pela presença de professores com altos níveis de certos atributos, tais como experiência de magistério e escolaridade. Tal relação corrobora a hipótese de que quanto maior a dispersão de idade dentro da turma, as dificuldades de se implantar projetos comuns de aprendizado são mais expressivas, tendo em vista que há uma maior diversidade de interesses. Nestas condições, o papel do professor parece ser fundamental para minimizar o efeito negativo das diversidades sobre desempenho individual.
Danielle Carusi Machado, Sergio Firpo, Gustavo Gonzaga.
TD n. 615, 08/08/2013
Popular press and some practitioners have warned against threats that buying risky
assets pose on agents saving for retirement, children education and other uses. This pa-
per shows that in a standard two-period general equilibrium model where some savers
have no risk-sharing motives, there exists a non-negligible set of economies (endow-
ments) and equilibria at which every economic agent is better off if some risky assets
are added to riskless securities. Numerical examples actually show that the measure of
the set of economies (endowments) with equilibrium allocations associated with trading
risky assets that are Pareto superior to when there are only riskless assets can be larger
than half the measure of the full set of economies.
Enrique Kawamura, Yves Balasko.
TD n. 614, 01/08/2013
We use data on immigrants who live in the United States to study the effects of exposure to hyperinflation on occupational choice. To do so, we calculate the number of years an individual had lived under hyperinflation before arriving to the US. We find that its marginal effect on the probability of being self-employed instead of wage-earner is 0.87 percentage point. This effect depends on the age individuals had when exposed to hyperinflation. In particular, it is stronger for individuals who experienced hyperinflation at an early age, but it vanishes for those over the age of 40. These results suggest that the macroeconomic environment an individual grows up in permanently affects his economic behavior.
João Manoel Pinho de Mello, Caio Waisman, Eduardo Zilberman.
TD n. 613, 17/07/2013
Neste artigo, introduz-se ao modelo de crescimento neoclássico a defasagem necessária para que o investimento público se consolide em capital público (processo time-to-build,0), assim como alíquotas tributárias distorcivas que se ajustam de acordo com a dívida acumulada pelo setor público. O objetivo é isolar quantitativamente o efeito do aumento do investimento público observado no Programa de Aceleração do Crescimento (PAC). Dependendo da defasagem associada ao processo time-to-build e da política de ajuste fiscal consideradas, o PAC pode ter induzido uma queda do produto entre 0,2% e 0,4% em um horizonte de até quatro anos.
Julio de Alencastro Graça Mereb, Eduardo Zilberman.
TD n. 612, 01/07/2013
A public job can be seen as a source of insurance against income risk. Indeed, many public employees have job stability, which is compounded with less volatile and more compressed wages. Hence, by increasing its number of public employees, the government enhances the overall degree of insurance in the economy. In this paper, we introduce public employment in a standard incomplete markets model with overlapping generations. The aim is to explore the welfare gains or losses due to a larger government, accounting for this extra source of insurance. In a model economy calibrated to Brazil, where public employment is around 13.5 percent of the workforce, we find that if the government relies on consumption taxes to balance its budget, the optimal size of public employment is nearly flat, ranging from 8 to 12 percent of the workforce. However, if the public employment is reduced from 12 to 8 percent, welfare losses due to a reduction in the degree of insurance are 2 percent, which are compensated by welfare gains due to level and inequality effects. This insurance effect is robust to a missepecification of the production technology associated with the public sector
Anna Carolina Saba dos Reis, Eduardo Zilberman.
TD n. 611, 01/06/2013
Yves Balasko.
TD n. 610, 30/05/2013
The Heckscher-Ohlin model with arbitrary number of goods, factors and
countries (consumers) and no restrictions on factor trading is shown to be
equivalent to an exchange model whose goods are the productive factors while
consumer’s indirect demands for factors are derived from their actual demands
for consumption goods. This equivalence enables one to import properties like
the pathconnectedness of the equilibrium manifold, the uniqueness of equilibrium
for sufficiently small volumes of trade and discontinuities of equilibrium
selection maps for large volumes of trade into the Heckscher-Ohlin model.
This equivalence also provides the proper theoretical background to the important
but so far purely empirical role played in international trade by the
volume of net trades in factor contents.
Yves Balasko.
TD n. 609, 29/05/2013
Social demand functions result from the budget constrained maximization of “social
preferences” or “other regarding preferences.” These preferences are non-selfish
in the sense that they also depend on other consumers’ wealth. This paper addresses
the robustness to wealth externalities of the classical general equilibrium model with
finite numbers of goods and consumers. The existence of equilibrium, the genericity of
regular economies and, at those regular economies, the finite odd number of equilibria
and the local continuity of equilibrium selection maps, and finally the identification
(or diffeomorphism) of the equilibrium manifold with a Euclidean space are shown
to be satisfied independently of the size of those wealth externalities provided total
resources are variable
Yves Balasko.
TD n. 608, 27/05/2013
It is widely believed that the presence of a large informal sector increases the efficiencycosts of social programs in developing countries. We develop a simple theoretical model of optimal unemployment insurance (UI) that specifies the efficiency–insurance tradeoff in the presence of informal job opportunities. We then combine the model with evidence drawn from 15 years of uniquely comprehensive administrative data to quantify the social costs of the UI program in Brazil. We first show that exogenous extensions of UI benefits led to falls in formal–sector reemployment rates due to offsetting rises in informal employment. However, because reemployment rates in the formal sector are low, most of the extra benefits were actually received by claimants who did not change their employment behavior. Consequently, only a fraction of the cost of UI extensions was due to perverse incentive effects and the efficiency costs were thus relatively small — only 20% as large as in the US, for example. Using variation in the relative size of the formal sector across different regions and over time in Brazil, we then show that the efficiency costs of UI extensions are actually larger in regions with a larger formal sector. Finally, we show that UI exhaustees have relatively low levels of disposable income, suggesting that the insurance value of longer benefits in Brazil may be sizeable. In sum, the results overturn the conventional wisdom, and indicate that efficiency considerations may in fact become more relevant as the formal sector expands.
François Gerard, Gustavo Gonzaga.
TD n. 607, 15/03/2013
We report two results. First, we evaluate the impact of a nationwide anti-firearm legislation passed
by the Brazilian Congress in December 2003 (Estatuto do Desarmamento, henceforth ED). Our identification
strategy hinges on the hypothesis that the law had stronger impact in places where gun prevalence was
higher in the baseline. We find evidence that homicides (reduced form) and firearms prevalence
(mechanism or first-stage) dropped faster in places with higher gun prevalence after the 2003. Using our
preferred estimates, the ED saved between 2,000 and 2,750 lives from 2004 through 2007 in cities with
more than 50,000 inhabitants in the state of São Paulo. Second, assuming the ED causes homicide only
through its impact on firearms prevalence, we recover a causal estimate of the impact of firearms on
homicides. One standard deviation in the prevalence of firearms reduces homicides by quarter of a
standard deviation. We find no impact of both ED and firearms on property crime in general or on
robberies.
João Manoel Pinho de Mello, Daniel Ricardo de Castro Cerqueira.
TD n. 605, 01/01/2013
We use data from a unique survey of members of drug-trafficking gangs in favelas (slums) of Rio de
Janeiro, Brazil, to characterize drug-trafficking jobs and study the selection into gangs, analyzing what
distinguishes gang-members from other youth living in favelas. We also estimate wage regressions for
gang-members and examine their career path: age at entry, progression within the gangs’ hierarchy, and
short- to medium-term outcomes. Individuals from lower socioeconomic background and with no
religious affiliation have higher probability of joining a gang, while those with problems at school and
early use of drugs join the gang at younger ages. Wages within the gang do not depend on education, but
are increasing with experience and involvement in gang-related violence. The two-year mortality rate in
the sample of gang-members reaches 20%, with the probability of death increasing with initial
involvement in gang violence and with personality traits associated with unruliness
Rodrigo Reis Soares, Leandro Siqueira Carvalho.
TD n. 604, 01/10/2012
The literature on excess return prediction has considered a wide array of estimation schemes, among them unrestricted and restricted regression coefficients. We consider bootstrap aggregation (bagging) to smooth parameter restrictions. Two types of restrictions are considered: positivity of the regression coefficient and positivity of the forecast. Bagging constrained estimators can have smaller asymptotic mean-squared prediction errors than forecasts from a restricted model without bagging. Monte Carlo simulations show that forecast gains can be achieved in realistic sample sizes for the stock return problem. In an empirical application using the data set of Campbell, J., and S. Thompson (2008): “Predicting the Equity Premium Out of Sample: Can Anything Beat the Historical Average?”, Review of Financial tudies 21, 1511-1531, we show that we can improve the forecast performance further by smoothing the restriction through bagging.
Eric Hillebrand, Tae-Hwy Lee , Marcelo Medeiros.
TD n. 603, 01/09/2012
Tendo em vista o padrão de comércio da economia brasileira, o aumento paulatino da
participação de bens importados na oferta de produtos industriais no País é simples e
inexorável decorrência lógica do processo de abertura. Mas a resistência política a esse
aumento de participação das importações vem sendo exacerbada pela perda de
competitividade da indústria de transformação que, só muito recentemente, deixou de
ser associada exclusivamente ao câmbio.
Passou agora a ser percebido com mais clareza que o aumento persistente do Custo
Brasil – decorrente, em boa parte, da elevação sem fim da carga tributária e das
deficiências dos três níveis de governo no desempenho das funções que lhes cabem –
vem tendo papel crucial na perda de competitividade. E certamente foi um grande
avanço que, afinal, o governo tenha entendido que algum esforço de desoneração fiscal
se tornara imprescindível. O que é lamentável é que as medidas de desoneração para
fazer face à perda de competitividade da indústria tenham sido tão mal concebidas.
Sem condições de conciliar seu projeto político com um programa de redução
horizontal, efetiva e substancial da carga tributária, o governo vem manipulando uma
política espalhafatosa e pouco transparente de desoneração da folha que, em meio a
muita poeira, pouco desonera. Em vez de simples redução da alíquota de contribuição
patronal, o que vem sendo oferecido é uma injustificável mudança de base fiscal.
Contribuição paga sobre faturamento e não mais sobre a folha de pagamento, com
alguma desoneração embutida na troca, e alíquotas fixadas setor a setor, na medida da
estridência do protesto de cada um. Arranjo peculiar e primitivo que pode transformar
o sistema tributário nacional numa colcha de retalhos ainda mais caótica do que já é.
Rogério Werneck.
TD n. 602, 07/08/2012
We study the asymptotic properties of the Adaptive LASSO (adaLASSO) in sparse,
high-dimensional, linear time-series models. We assume both the number of covariates in the
model and candidate variables can increase with the number of observations and the number of
candidate variables is, possibly, larger than the number of observations. We show the adaLASSO
consistently chooses the relevant variables as the number of observations increases (model selection
consistency,0), and has the oracle property, even when the errors are non-Gaussian and conditionally
heteroskedastic. A simulation study shows the method performs well in very general
settings. Finally, we consider two applications: in the first one the goal is to forecast quarterly
US inflation one-step ahead, and in the second we are interested in the excess return of the S&P
500 index. The method used outperforms the usual benchmarks in the literature.
Marcelo Medeiros, Eduardo F. Mendes.
TD n. 593, 01/08/2012
Versão revista e recebeu o título "Informal Labor and the Cost of Social Programs: Evidence from 15 Years of Unemployment Insurance in Brazil" e difulgada como Texto para Discussão no. 608, 2013.
François Gerard, Gustavo Gonzaga.
TD n. 601, 01/07/2012
This paper analyzes the impact of rainfall fluctuations during the gestational period on health at birth.
We concentrate on the semiarid region of Northeastern Brazil to highlight the role of water scarcity as a determinant of early life health. We find that negative rainfall shocks are robustly correlated with higher infant mortality, lower birth weight, and shorter gestation periods. Mortality effects are concentrated on intestinal infections and malnutrition, and are greatly minimized when the local public health infrastructure is sufficiently developed (municipality coverage of piped water and sanitation). We also find that effects are stronger during the fetal period (2o. trimester of gestation,0), for children born during the dry season, and for mortality in the first 6 months of life. The results seem to be driven by water scarcity per se, and not by reduced agricultural production. Our estimates suggest that expansions in public health infrastructure would be a cost-effective way of reducing the response of infant mortality to rainfall shocks in the Brazilian semiarid.
Rudi Rocha, Rodrigo Reis Soares.