697 resultados para consumption volatility
Resumo:
In recent years, a large and expanding literature has examined the properties of developing economies with regard to the macroeconomic cycle.1 One such property that is characteristic of developing economies is large fluctuations in consumption. Meanwhile, aid for the low income countries is extremely volatile, and under certain circumstances, the volatile aid amplifies the consumption volatility. This document examines whether it is possible that the volatile aid yields high consumption volatility in African countries that constitute the majority of the low income countries. Our numerical analysis reveals that the strongly influential aid disbursements yield a considerably large fluctuation in consumption.
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We take a new approach to the study of the impact of EMU on consumption smoothing. Rather than relying on inferences based on the behavior of consumption levels or growth, we focus on consumption volatility and therefore on smoothing more directly. Consequently, we find that even though EMU tends to smooth consumption, it is not through cross-country property and claims. Rather it comes through the promotion of the tradability of goods, capital in particular: specifically, the encouragement of price competition, contestable home markets, ability to borrow and buy insurance at home, and the harmonization of regulations. Some of the consumption smoothing may also depend on EU membership rather than EMU as such but EMU adds to it. As a fundamental part of the analysis, the paper uses a new index of currency union which focuses on the ratio of trade with other countries sharing the same currency relative to total foreign trade.
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We study the quantitative properties of a dynamic general equilibrium model in which agents face both idiosyncratic and aggregate income risk, state-dependent borrowing constraints that bind in some but not all periods and markets are incomplete. Optimal individual consumption-savings plans and equilibrium asset prices are computed under various assumptions about income uncertainty. Then we investigate whether our general equilibrium model with incomplete markets replicates two empirical observations: the high correlation between individual consumption and individual income, and the equity premium puzzle. We find that, when the driving processes are calibrated according to the data from wage income in different sectors of the US economy, the results move in the direction of explaining these observations, but the model falls short of explaining the observed correlations quantitatively. If the incomes of agents are assumed independent of each other, the observations can be explained quantitatively.
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During the last few decades, many emerging markets have lifted restrictions on cross-borderfinancial transactions. The conventional view was that this would allow these countries to: (i)receive capital inflows from advanced countries that would finance higher investment and growth;(ii) insure against aggregate shocks and reduce consumption volatility; and (iii) accelerate thedevelopment of domestic financial markets and achieve a more efficient domestic allocationof capital and better sharing of individual risks. However, the evidence suggests that thisconventional view was wrong.In this paper, we present a simple model that can account for the observed effects of financialliberalization. The model emphasizes the role of imperfect enforcement of domestic debts and theinteractions between domestic and international financial transactions. In the model, financialliberalization might lead to different outcomes: (i) domestic capital flight and ambiguous effectson net capital flows, investment, and growth; (ii) large capital inflows and higher investmentand growth; or (iii) volatile capital flows and unstable domestic financial markets. The modelshows how these outcomes depend on the level of development, the depth of domestic financialmarkets, and the quality of institutions.
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Introducing bounded rationality in a standard consumption-based asset pricing model with time separable preferences strongly improves empirical performance. Learning causes momentum and mean reversion of returns and thereby excess volatility, persistence of price-dividend ratios, long-horizon return predictability and a risk premium, as in the habit model of Campbell and Cochrane (1999), but for lower risk aversion. This is obtained, even though our learning scheme introduces just one free parameter and we only consider learning schemes that imply small deviations from full rationality. The findings are robust to the learning rule used and other model features. What is key is that agents forecast future stock prices using past information on prices.
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This paper analyzes empirically the volatility of consumption-based stochastic discount factors as a measure of implicit economic fears by studying its relationship with future economic and stock market cycles. Time-varying economic fears seem to be well captured by the volatility of stochastic discount factors. In particular, the volatility of recursive utility-based stochastic discount factor with contemporaneous growth explains between 9 and 34 percent of future changes in industrial production at short and long horizons respectively. They also explain ex-ante uncertainty and risk aversion. However, future stock market cycles are better explained by a similar stochastic discount factor with long-run consumption growth. This specification of the stochastic discount factor presents higher volatility and lower pricing errors than the specification with contemporaneous consumption growth.
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Ethanol consumption damages the prostate, and testosterone is known by anti-inflammatory role. The cytokines were investigated in the plasma and ventral prostate of UChB rats submitted or not to testosterone therapy by ELISA and Western blot, respectively. Additionally, inflammatory foci and mast cells were identified in the ventral prostate slides stained by hematoxylin and eosin and toluidine blue, respectively. Inflammatory foci were found in the ethanol-treated animals and absent after testosterone therapy. Plasma levels of IL-6 and IL-10 were not changed while TNFα and TFG-β1 were increased in the animals submitted testosterone therapy. Regarding to ventral prostate, IL-6 did not alter, while IL-10, TNFα, and TFG-β1 were increased after testosterone therapy. Ethanol increases NFR2 in addition to high number of intact and degranulated mast cell which were reduced after testosterone therapy. So, ethanol and testosterone differentially modulates the cytokines in the plasma and prostate.
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To evaluate associations between polymorphisms of the N-acetyltransferase 2 (NAT2), human 8-oxoguanine glycosylase 1 (hOGG1) and X-ray repair cross-complementing protein 1 (XRCC1) genes and risk of upper aerodigestive tract (UADT) cancer. A case-control study involving 117 cases and 224 controls was undertaken. The NAT2 gene polymorphisms were genotyped by automated sequencing and XRCC1 Arg399Gln and hOGG1 Ser326Cys polymorphisms were determined by Polymerase Chain Reaction followed by Restriction Fragment Length Polymorphism (PCR-RFLP) methods. Slow metabolization phenotype was significantly associated as a risk factor for the development of UADT cancer (p=0.038). Furthermore, haplotype of slow metabolization was also associated with UADT cancer (p=0.014). The hOGG1 Ser326Cys polymorphism (CG or GG vs. CC genotypes) was shown as a protective factor against UADT cancer in moderate smokers (p=0.031). The XRCC1 Arg399Gln polymorphism (GA or AA vs. GG genotypes), in turn, was a protective factor against UADT cancer only among never-drinkers (p=0.048). Interactions involving NAT2, XRCC1 Arg399Gln and hOGG1 Ser326Cys polymorphisms may modulate the risk of UADT cancer in this population.
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Chronic ethanol consumption leads to reproductive damages, since it can act directly in the tissues or indirectly, causing a hormonal imbalance. Prostate is a hormone-dependent gland and, consequently, susceptible to ethanol. The potential of testosterone therapy in the ethanol-related disorders was investigated in the prostate microenvironment. UChB rats aged 90 days were divided into 2 experimental groups (n=20): C: drinking water only and EtOH: drinking 10% (v/v) ethanol at >2 g/kg body weight/day+water. At 150 days old, 10 rats from each group received subcutaneous injections of testosterone cypionate (5 mg/kg body weight) diluted in corn oil every other day for 4 weeks, constituting T and EtOH+T, while the remaining animals received corn oil as vehicle. Animals were euthanized at 180 days old, by decapitation. Blood was collected to obtain hormone concentrations and ventral prostate was dissected and processed for light microscope and molecular analyses. Ventral prostate weight, plasma testosterone and DHT and intraprostatic testosterone concentrations were increased after testosterone treatment. Plasma estradiol level was reduced in the EtOH+T. Inflammatory foci, metaplasia and epithelial atrophy were constantly found in the prostate of EtOH and were not observed after hormonal therapy. No differences were found in the expression of AR, ERβ and DACH-1. Additionally, testosterone treatment down-regulated ERα and increased the e-cadherin and α-actinin immunoreactivities. Testosterone was able to reverse damages caused by ethanol consumption in the prostate microenvironment and becomes a possible target to be investigated to ethanol-related disorders.
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Epidemiological studies have suggested that cola beverage consumption may affect bone metabolism and increase bone fracture risk. Experimental evidence linking cola beverage consumption to deleterious effects on bone is lacking. Herein, we investigated whether cola beverage consumption from weaning to early puberty delays the rate of reparative bone formation inside the socket of an extracted tooth in rats. Twenty male Wistar rats received cola beverage (cola group) or tap water (control group) ad libitum from the age of 23 days until tooth extraction at 42 days and euthanasia 2 and 3 weeks later. The neoformed bone volume inside the alveolar socket was estimated in semi-serial longitudinal sections using a quantitative differential point-counting method. Histological examination suggested a decrease in the osteogenic process within the tooth sockets of rats from both cola groups, which had thinner and sparser new bone trabeculae. Histometric data confirmed that alveolar bone healing was significantly delayed in cola-fed rats at three weeks after tooth extraction (ANOVA, p = 0.0006, followed by Tukey's test, p < 0.01). Although the results of studies in rats cannot be extrapolated directly to human clinical dentistry, the present study provides evidence that cola beverage consumption negatively affect maxillary bone formation.
Drug consumption among medical students in São Paulo, Brazil: influences of gender and academic year
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OBJECTIVE: To analyze alcohol, tobacco and other drug use among medical students. METHOD: Over a five-year period (1996-2001), we evaluated 457 students at the Universidade de São Paulo School of Medicine, located in São Paulo, Brazil. The students participated by filling out an anonymous questionnaire on drug use (lifetime, previous 12 months and previous 30 days). The influence that gender and academic year have on drug use was also analyzed. RESULTS: During the study period, there was an increase in the use of illicit drugs, especially inhalants and amphetamines, among the medical students evaluated. Drug use (except that of marijuana and inhalants) was comparable between the genders, and academic year was an important influencing factor. DISCUSSION: Increased inhalant use was observed among the medical students, especially among males and students in the early undergraduate years. This is suggestive of a specific behavioral pattern among medical students. Our findings corroborate those of previous studies. CONCLUSION: Inhalant use is on the rise among medical students at the Universidade de São Paulo School of Medicine. Because of the negative health effects of illicit drug use, further studies are needed in order to deepen the understanding of this phenomenon and to facilitate the development of preventive measures.
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The aim of this study was to validate the intake of carotenoids, fruits and vegetables estimated by the Food Frequency Questionnaire for Adolescents (FFQA) using the method of triads. Blood samples were collected from 80 elementary school adolescents to assess serum levels of β-carotene. Partial correlation coefficients (r) were calculated between an estimated intake of carotenoids, fruits and vegetables and the serum levels of β-carotene. Validity coefficients were calculated using the method of triads. With the exception of carotenoids, partial r from the food frequency questionnaire (FFQ) were greater than those of the 24-hour recall (24hR). The fruit/vegetable group showed the highest partial r for the FFQ (r = 0.235) and the 24hR (r = 0.137). The highest validity coefficient was obtained for the vegetable group, as assessed by the FFQ (r = 0.873). On average, the validity coefficient values for the FFQ were greater than those obtained for the 24hR or the β-carotene serum levels. The FFQA is an accurate tool for estimating the intake of carotenoids, fruits and vegetables in this population group.
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Information on fruits and vegetables consumption in Brazil in the three levels of dietary data was analyzed and compared. Data about national supply came from Food Balance Sheets compiled by the FAO; household availability information was obtained from the Brazilian National Household Budget Survey (HBS); and actual intake information came from a large individual dietary intake survey that was representative of the adult population of São Paulo city. All sources of information were collected between 2002 and 2003. A subset of the HBS, representative of São Paulo city, was used in our analysis in order to improve the quality of the comparison with actual intake data. The ratio of national supply to household availability of fruits and vegetables was 2.6 while the ratio of national supply to actual intake was 4.0. The discrepancy ratio in the comparison between household availability and actual intake was smaller, 1.6. While the use of supply and availability data has advantages, as lower cost, must be taken into account that these sources tend to overestimate actual intake of fruits and vegetables.
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Realizou-se um estudo do tipo caso-controle de base hospitalar no Município de João Pessoa, Paraíba, Brasil. Participaram 183 indivíduos (89 casos e 94 controles) na faixa etária entre 30 e 80 anos, com pareamento por idade. O consumo alimentar de casos e controles foi avaliado por alimentos e grupos de alimentos categorizados em tercis de consumo. A estimativa dos valores da odds ratio (OR) e intervalos de confiança de 95% (IC95%) foi realizada por regressão logística múltipla não-condicional. O consumo de frutas e sucos, feijão e leite e derivados apresentou uma forte associação com a redução no risco de câncer de mama. O consumo de carnes vermelhas e de carnes fritas esteve positivamente associado ao risco de câncer de mama (carne vermelha - OR = 4.30; IC95%: 1,74-10,67; p = 0,00). Não foi observada associação entre o consumo dos grupos de vegetais e embutidos com o câncer de mama. Carne vermelha e carnes fritas podem ser fatores de risco, e o consumo de frutas, feijão e leite e derivados pode atuar como protetor do câncer de mama