Three Essays on the Credit Dimension of Monetary Policy

This thesis focus on the credit dimensions of monetary policy. The topic has been an area of active research since the financial crisis of 2008 and 2009, The chapters can be grouped in terms of the questions that motivated them. For the first and the second, it was "Why do Central Banks in emerging market economies intervene in credit markets in response to external shocks?" while for the third the question is more general "Why do Central Banks intervene in credit markets?" In Chapter 1, we describe that, during the financial crisis of 2008-2009, to respond to a sudden stop in capital flows, many central banks in emerging market economies relied on credit policies. We build a quantitative small open economy model to study these credit policies. The main innovation of our setup is the presence of two imperfect credit markets, one domestic and the other international, and of two types of firms. The exporter is assumed to have access to both credit markets, while the wholesale firm can only borrow in the domestic market. During a sudden stop, exporters, faced with higher spreads for international credit lines, repay part of their foreign debt, tap the local market for funds and cause spreads to increase in the domestic market. This increases financing costs for all firms, causes a deterioration of the balance of payments and depresses output. Calibrating the model to match Brazilian data, we assess the effects of two policies implemented by the Central Bank of Brazil: (i) lending to exporters using previously accumulated foreign-exchange reserves and (ii) expanding credit in order to reduce spreads in the domestic market. The model suggests that both policies probably raised GDP, but that the latter may well have decreased welfare. Moreover, had the central bank not been able to use foreign reserves as the source of funding, lending to exporters would also have reduced welfare. In Chapter 2, we expand our focus to the fact that, during the crisis, the emerging markets economies faced a large decline in their terms of trade and an increase in the interest rate they could borrow from abroad. As their counterparts in developed economies, policymarkers intervened in credit markets. A common ground behind the interventions seems to be failures in the banking system. We build a quantitative small open economy model with domestic financial intermediation to study these credit policies. The main innovation of our setup is the presence of a domestic banking system. In this structure, four main channels link external shocks to the financial sector: (1) the profitability of the export sector, (2) asset prices, (3) bank's borrowing cost and (4) the balance sheet position of banks as they hold foreign currency denominated debt. For the calibration we consider, based on Brazilian data, the domestic financial sector has the largest amplification effect in response to an increase in the international interest rate and the corresponding decline in assets price is the main channel. Hence credit interventions are most powerful in response to this type of a shock, reducing by 30% the initial GDP fall. The model is general and appropriate to address several questions. We illustrate that by showing that it can replicate standard business cycle properties and to discuss conventional monetary policy in the context sudden stops, when the domestic banking system is often at the epicenter of the crisis. In Chapter 3, we first note that a number of recent theoretical papers show that margins can affect asset prices. Such results are important, for example, to understand the unconventional polices implemented by the Fed during the great recession of 2007-2010. However, empirical evidence is still scarce. We contribute to fill this gap. We show that an aggregate margin-related factor is able to predict future excess returns of the SP 500 and that stocks with high exposures to the cost of buying on margin pay on average higher returns

A real options model with entry and exit strategies and with uncertain, sequential investment and construction time

Esta dissertação desenvolve um modelo de opções reais com investimento incerto, sequencial e com tempo de construção. Incorpora-se no modelo as opções reais de investir e abandonar a atividade. O modelo aborda o problema de maximização de uma empresa diante de um investimento com as características citadas. A equação diferencial do ativo é obtida utilizando programação dinâmica e avaliação neutra ao risco. Em particular, para o período da construção, a equação diferencial é parcial e elíptica, o que demandou a utilização de métodos numéricos. Os principais resultados da dissertação são que, ao contrário do que boa parte da literatura sobre opções reais afirma, com investimento sequencial e tempo de construção, a regra do NPV pode não gerar equívocos significativos e o aumento da incerteza pode aumentar o investimento.This dissertation solves a real option model with uncertain and sequential investment, which takes time to build. The firm has an option to invest and an option to abandon the activity. Using dynamic programming and equivalent risk neutral valuation, we obtain the differential equation of the asset. The differential equation for the asset during the construction period is partial and elliptical, which required the use of numerical methods. The numerical simulation shows two important results: first, the naive NPV rule may not be misleading as the real option theory suggests; and, second, more uncertainty can reduce the price that triggers the investment

Pertencimento à escola: sentidos atribuídos por alunos do ensino fundamental II

Ancorado na perspectiva Bioecológica do Desenvolvimento Humano (Urie Bronfenbrenner 1917-2005), o estudo descritivo objetivou analisar os sentidos de pertencimento à escola, atribuídos por alunos do Ensino Fundamental II com histórico de reprovação, de uma escola pública paranaense. Participaram 19 alunos (6º ao 9º ano de 11 a 15 anos). O estudo, de abordagem qualitativa, teve como instrumentos investigativos: entrevista semiestruturada e produção de representações pictóricas com legendas. Os resultados constituíram três categorias: 1) Representação de escola como espaço de acolhimento (11 participantes) ou aversividade (8 participantes); 2) Relação com outros alunos: pertencimento (14 participantes) ou exclusão (5 participantes); 3) Relação com professores: relacionamento amistoso (13 participantes) ou dificultoso (6 participantes). Considerando-se que os eventos vividos na escola se integram aos demais microssistemas de desenvolvimento do aluno, por processos contextualmente produzidos, o pertencimento do aluno à escola e os sentidos que desenvolve o afetam para além do contexto escolar. Observou-se, portanto, a escola como microssistema produtor de um conjunto de significados que vincula o sentido de pertencimento à escola e ao saber científico. Compreender de modo integrado os vários elementos que constituem o microssistema escolar possibilita a elaboração de práticas e políticas educacionais que enfrentem situações desfavoráveis ao aprender e favoreçam sentidos positivos acerca da Escola

Bicarbonato de sódio e HEPES como tampões para o resfrigeração de sêmen de pôneis

The composition of semen diluents can modify its viability during cooling. The buffering effects of HEPES and sodium bicarbonate were evaluated considering the pH and sperm viability. The semen of seven adult Brazilian ponies was evaluated before and after cooling at 5oC for 24 h and 48 h. A non-buffered skim milk powder extender (C) and the same extender buffered with sodium bicarbonate (SB) and HEPES (H) were used. After dilution, semen (three ejaculates/pony) was centrifuged and the seminal plasma discarded. Sperm was then diluted with SB, H or C and its concentration adjusted to 50 x 106 sptz/mL. Progressive motility evaluated after dilution showed similar results with all extenders (71.42% (SB), 74.28% (H), and 74.52% (C)). Sperm motility was evaluated 24 h and 48 h after cooling for SB (44.76% and 25.23%), H (51.42% and 38.09%) and C (54.05% and 41.66%, respectively). Plasma membrane integrity was similar after exposure to the three extenders (62.71% (SB), 68.76% (H), and 69.23% (C)). Mitochondrial activity was higher in SB immediately after dilution (SB= 1.05nm, H= 0.81nm, C= 0.79nm), and after 24 h (0.83nm (SB), 0.73nm (H) and 0.64nm (C)). After 48 h, the mitochondrial activity decreased to 0.72nm (SB), 0.69nm (H), and 0.63nm (C) (P > 0.05). The pH, osmolarity and pH after 48 h of cooling of the diluted semen were higher in SB (8; 382; 7.9), intermediate in H (7.5; 362; 7.32) and lower in C (7.16; 350; 7.07). Lipid peroxidation and its induction were similar in all groups. Data were analyzed by analysis of variance (ANOVA), and Duncan’s test was used to evaluate the significant differences (P 0.05). O pH, a osmolaridade e o pH do sêmen diluído após as 48 h de refrigeração foram maiores em SB (8; 382; 7,9), intermediário em H (7,5; 362; 7,32) e menor em C (7,16; 350; 7,07). A peroxidação lipídica e sua indução foram semelhantes em todos os grupos. As médias foram avaliadas através de análise de variância (ANOVA) e o Teste Duncan foi utilizado para analisar as diferenças significativas (P < 0.05). O bicarbonato de sódio reduziu a motilidade progressiva e aumentou o pH do sêmen. O diluente C foi considerado mais adequado para uso imediato na inseminação artificial. O diluente não tamponado e tampado com HEPES foram considerados apropriados para o resfriamento de sêmen de equino durante 48 h a 5°C

Characterization, agricultural potential, and perspectives for the management of light soils in Brazil

Os solos leves ocupam cerca de 8% do território brasileiro e são epecialmente expressivos na nova e na última fronteira agrícola do país: a região de Matopiba, nos estados do Maranhão, do Tocantins, do Piauí e da Bahia, onde representam 20% da área. Esses solos enquadram-se nas classes texturais areia e areia franca ou francoarenosa, até a profundidade de 0,75 m ou mais, e são representados principalmente pelos Neossolos Quartzarênicos e, em parte, por Latossolos e Argissolos. O entendimento do funcionamento desses solos depende do estabelecimento de critérios distintivos sobre: dinâmica da matéria orgânica; teor e mineralogia da fração argila; teores de areia grossa e de areia total, em relação aos de areia fina; diâmetro médio da fração areia; e capacidade de retenção de água. Esses critérios podem contribuir para o zoneamento e para o manejo conservacionista e da fertilidade dos solos leves, bem como para estimação de seu potencial agrícola. Sistemas integrados de produção, como os de integração lavoura-pecuária e lavoura-pecuária-floresta, além do plantio direto com rotação de culturas, dos plantios florestais mistos com espécies leguminosas, e do uso de adubos verdes e cultivos de cobertura, são relevantes para o manejo adequado desses solos. O objetivo deste artigo de revisão foi caracterizar os solos leves e apontar os principais desafios em relação a seu potencial agrícola, a seu manejo e conservação e sua fertilidade, frente à expansão e à consolidação da nova fronteira agrícola.Light soils occupy 8% of the Brazilian territory and are especially expressive in the new and last agricultural frontier in Brazil: the Matopiba region – in the states of Maranhão, Tocantins, Piauí, and Bahia –, where they represent 20% of the area. These soils fit into the textural classes of sand, loamy sand, and sandy loam, down to 0.75-m soil depth or deeper, and they are mainly represented by Entisols (Quartzipsamments), and partly by Oxisols and Ultisols. The understanding of soil functioning depends on the establishment of distinguishing criteria for: organic matter dynamics; content and mineralogy of the clay fraction; coarse sand and total sand contents, in relation to those of fine sand; mean diameter of the sand fraction; and water retention capacity. These criteria can contribute for the zoning and for the conservationist and fertility management of light soils, as well as for the estimation of their agricultural potential. Integrated production systems, such as, crop-livestock and crop-livestock-forestry integration, besides no-tillage with crop rotation, mixed forestry planting with legumes, and the use of green manure and cover crops, are relevant for the proper management of these soils. The objective of this review was to characterize light soils and to highlight the main challenges regarding their agricultural potential and their conservation and fertility managements, in face of the expansion and consolidation of the new Brazilian agricultural frontier