58 resultados para neutral fermion
Resumo:
We report on a series of experiments that test the effects of an uncertain supply on the formation of bids and prices in sequential first-price auctions with private-independent values and unit-demands. Supply is assumed uncertain when buyers do not know the exact number of units to be sold (i.e., the length of the sequence). Although we observe a non-monotone behavior when supply is certain and an important overbidding, the data qualitatively support our price trend predictions and the risk neutral Nash equilibrium model of bidding for the last stage of a sequence, whether supply is certain or not. Our study shows that behavior in these markets changes significantly with the presence of an uncertain supply, and that it can be explained by assuming that bidders formulate pessimistic beliefs about the occurrence of another stage.
Resumo:
In this paper we follow the tradition of applied general equilibrium modelling of the Walrasian static variety to study the empirical viability of a double dividend (green, welfare, and employment) in the Spanish economy. We consider a counterfactual scenario in which an ecotax is levied on the intermediate and final use of energy goods. Under a revenue neutral assumption, we evaluate the real income and employment impact of lowering payroll taxes. To appraise to what extent the model structure and behavioural assumptions may influence the results, we perform simulations under a range of alternative model and policy scenarios. We conclude that a double dividend –better environmental quality, as measured by reduced CO2 emissions, and improved levels of employment– may be an achievable goal of economic policy.
Resumo:
We use results from the literature on the determinants of price-cost margins to derive an equation relating labor's share of national income to the inflation rate (as well as to the output gap, the unemployment rate and the capital stock per worker). The equation is tested with a panel of 15 OECD countries. We obtain a robust positive relationship between inflation and the labor share. Our results suggest that disinflation is not distributively neutral, provide empirical support for the distinct concern about price stability shown by trade unions and employers' organizations, and help explaining the negative impact of inflation on growth.
Resumo:
Compliance is an important issue in environmental regulation. In this paper, we discuss some of the key elements of the problem and analyze a situation where emissions are not random and firms are risk-neutral. We study the firm's decision on emissions and compliance when the environmental regulation is based on standards and the enforcement agency audits the firm with a certain probability. We then compare total emissions when environmental regulation is based on different instruments: standards, taxes, and tradable permits. We show that when compliance is an issue, environmental taxes are superior to the other instruments. We also analyze the (static) efficiency of the solution.
Resumo:
This paper is a positive analysis of the driving forces in interdisciplinary research. I take the perspective of a research institution that has to decide how to apply its resources among the production of two types of knowledge: specialized or interdisciplinary. Using a prize mechanism of compensation, I show that the choice of interdisciplinarity is compatible with profit maximization when the requirement for the production is sufficiently demanding, and when the new interdisciplinary field is not too neutral. Productive gains due to complementarities of efforts is the main advantage of interdisciplinary organization.
Resumo:
One of the main implications of the efficient market hypothesis (EMH) is that expected future returns on financial assets are not predictable if investors are risk neutral. In this paper we argue that financial time series offer more information than that this hypothesis seems to supply. In particular we postulate that runs of very large returns can be predictable for small time periods. In order to prove this we propose a TAR(3,1)-GARCH(1,1) model that is able to describe two different types of extreme events: a first type generated by large uncertainty regimes where runs of extremes are not predictable and a second type where extremes come from isolated dread/joy events. This model is new in the literature in nonlinear processes. Its novelty resides on two features of the model that make it different from previous TAR methodologies. The regimes are motivated by the occurrence of extreme values and the threshold variable is defined by the shock affecting the process in the preceding period. In this way this model is able to uncover dependence and clustering of extremes in high as well as in low volatility periods. This model is tested with data from General Motors stocks prices corresponding to two crises that had a substantial impact in financial markets worldwide; the Black Monday of October 1987 and September 11th, 2001. By analyzing the periods around these crises we find evidence of statistical significance of our model and thereby of predictability of extremes for September 11th but not for Black Monday. These findings support the hypotheses of a big negative event producing runs of negative returns in the first case, and of the burst of a worldwide stock market bubble in the second example. JEL classification: C12; C15; C22; C51 Keywords and Phrases: asymmetries, crises, extreme values, hypothesis testing, leverage effect, nonlinearities, threshold models
Resumo:
Els dominis d’activació (ADs) de les procarboxipeptidases de la subfamília A/B sempre han sorprès ja que representen una quarta part del proenzim. S’han realitzat alguns estudis per intentar descobrir-ne alguna possible funció alternativa, però no han estat fructífers. El descobriment de l’elevada velocitat de plegament del domini d’activació de la procarboxipeptidasa A2 humana, (ADA2h), emperò, va portar a proposar la possibilitat de que realitzessin una funció d’assistència al plegament del domini enzimàtic. Posteriorment, l’anàlisi del plegament d’ADA2h a pH baix va revelar la capacitat d’aquest domini per formar fibres amiloides, a més de demostrar que un increment de l’estabilitat proteica podia prevenir la formació d’aquests agregats. La profunda caracterització del plegament d’ADA2h va fer que aquesta proteïna fos un bon model amiloidogènic, de manera que es van proposar un seguit d’experiments que s’han desenvolupat en el present treball per tal de conèixer millor aquest procés. S’han dut a terme estudis cinètics d’agregació per tal de valorar la contribució dels diferents aminoàcids de la seqüència polipeptídica, utilitzant 29 variants puntuals d’ADA2h. Es va eliminar la contribució de l’estabilitat mitjançant la utilització d’urea, i per dicroïsme circular conjuntament amb un aparell de flux detingut, es van obtenir dues velocitats diferents, v1 i v2, que corresponen a la formació d’un intermediari i a la seva reorganització, respectivament. Experiments complementaris utilitzant espectroscòpia d’infraroig (IR) revelaren la reorganització de l’estat natiu (en aquest cas) per a donar la forma agregada. Les cinètiques d’IR van mostrar que ADA2h forma l’estructura _ típica de les fibres amiloides, previ desplegament les seves hèlixs-_. Finalment, s’han realitzat estudis de biocomputació per tal d’esbrinar possibles funcions alternatives dels ADs. Les superposicions estructurals semblen mostrar similaritat dels ADs amb dominis de reconeixement d’RNA (RRM). Aquesta hipòtesi s’ha comprovat experimentalment amb ADA4h, mostrant una dèbil, però existent, unió a RNA.
Resumo:
The objective of this paper is to correct and improve the results obtained by Van der Ploeg (1984a, 1984b) and utilized in the theoretical literature related to feedback stochastic optimal control sensitive to constant exogenous risk-aversion (see, Jacobson, 1973, Karp, 1987 and Whittle, 1981, 1989, 1990, among others) or to the classic context of risk-neutral decision-makers (see, Chow, 1973, 1976a, 1976b, 1977, 1978, 1981, 1993). More realistic and attractive, this new approach is placed in the context of a time-varying endogenous risk-aversion which is under the control of the decision-maker. It has strong qualitative implications on the agent's optimal policy during the entire planning horizon.
Resumo:
Treball de recerca realitzat per un alumne d’ensenyament secundari i guardonat amb un Premi CIRIT per fomentar l'esperit científic del Jovent l’any 2008. La hipòtesi de partida és que les plantes de blat de moro no modificades genèticament són més resistents a tres paràmetres que no pas les transgèniques. Aquests tres paràmetres són: un augment de temperatura, reg amb aigua salada i absència d’aigua. Inclou també una incursió al món dels transgènics i la polèmica actual, concretada en les entrevistes fetes, amb l’objectiu de tenir criteri amb coneixement de causa. Es conclou que el món científic, que se suposa objectiu i neutral, en el tema dels transgènics és confús i que la majoria de la població està desinformada. Els moviments de conscienciació ciutadana fan de contrapunt als possibles abusos de les multinacionals. La situació dels agricultors és de dependència de les multinacionals. Gràcies als transgènics però s’ha pogut avançar en el camp dels medicaments. Referent a l’experiment, no té valor científic perquè la mostra no és representativa i els resultats són atzarosos.
Dynamic stackelberg game with risk-averse players: optimal risk-sharing under asymmetric information
Resumo:
The objective of this paper is to clarify the interactive nature of the leader-follower relationship when both players are endogenously risk-averse. The analysis is placed in the context of a dynamic closed-loop Stackelberg game with private information. The case of a risk-neutral leader, very often discussed in the literature, is only a borderline possibility in the present study. Each player in the game is characterized by a risk-averse type which is unknown to his opponent. The goal of the leader is to implement an optimal incentive compatible risk-sharing contract. The proposed approach provides a qualitative analysis of adaptive risk behavior profiles for asymmetrically informed players in the context of dynamic strategic interactions modelled as incentive Stackelberg games.
Resumo:
Esta investigación está basada en la intención de crear una guía de entrenamiento para el actor, que busca asumir un compromiso con su cuerpo, como instrumento para la creación escénica. El trabajo del actor-actriz está irremediablemente vinculado a su cuerpo, todo lo humano se enmarca en un cuerpo vivido, en el espacio y en el tiempo, no es algo neutral. Sabemos que cada actor-actriz, tiene una noción de su esquema corporal, entendiendo por esquema corporal la representación en imágenes de los diferentes segmentos corporales que conforman nuestro cuerpo y la percepción de éste esquema corporal, estará en función de su capacidad de auto-percepción
Resumo:
We examine the evolution of monetary policy rules in a group of inflation targeting countries (Australia, Canada, New Zealand, Sweden and the United Kingdom) applying moment- based estimator at time-varying parameter model with endogenous regressors. Using this novel flexible framework, our main findings are threefold. First, monetary policy rules change gradually pointing to the importance of applying time-varying estimation framework. Second, the interest rate smoothing parameter is much lower that what previous time-invariant estimates of policy rules typically report. External factors matter for all countries, albeit the importance of exchange rate diminishes after the adoption of inflation targeting. Third, the response of interest rates on inflation is particularly strong during the periods, when central bankers want to break the record of high inflation such as in the U.K. or in Australia at the beginning of 1980s. Contrary to common wisdom, the response becomes less aggressive after the adoption of inflation targeting suggesting the positive effect of this regime on anchoring inflation expectations. This result is supported by our finding that inflation persistence as well as policy neutral rate typically decreased after the adoption of inflation targeting.
Resumo:
Studies show that feeding patterns, environmental conditions, and pet management mainly affect animal health, behavior and welfare. However, little epidemiologic data exist about pet dog feeding habits and management and canine behavior, especially aggression. Moreover, it is well known that serotonin is involved in aggression: a diet low in tryptophan (serotonin precursor) with high levels of neutral amino-acids could decrease the central levels of serotonin and increase the expression of aggression and impulsiveness in several domestic animals. oreover, brain levels of serotonin in humans and other species can be increased by physical activity. In this study we alysed the effects of diet management, supplementation and regular physical activity on oncentration of serotonin in a population of non aggressive dogs. The general aim of the study is to determine the effect of environmental factors on the dogs’ feeding habits as well as the relationship between the type of food provided and management and behavioral problems in dogs. The specific objectives were: characterization and comparison of different physiological and blood parameters between dogs with and without behavior pathologies. Observation of the impact of the diet and managment factors (exercise, education) on those parameters and on dog’s behavior, with particular attention to aggression. This study is divided into three phases, according with the objectives. Firstly, characterization of the dogs’ characteristics and serics profiles on the basis of the blood tests. Comparison between the values noticed on animals without any behavior pathology and animals with behavior disorder to point out the difference between the biochemical parameters of the two groups. Secondly, the purpose of the second phase is to verify whether a type of food is able to affect the biochemical paramenters of a population of non-aggressive dogs. Thirdly, the goal is to evaluate the effects of different diet factors, management and physical exercise on the canine aggression.
Resumo:
First: A continuous-time version of Kyle's model (Kyle 1985), known as the Back's model (Back 1992), of asset pricing with asymmetric information, is studied. A larger class of price processes and of noise traders' processes are studied. The price process, as in Kyle's model, is allowed to depend on the path of the market order. The process of the noise traders' is an inhomogeneous Lévy process. Solutions are found by the Hamilton-Jacobi-Bellman equations. With the insider being risk-neutral, the price pressure is constant, and there is no equilibirium in the presence of jumps. If the insider is risk-averse, there is no equilibirium in the presence of either jumps or drifts. Also, it is analised when the release time is unknown. A general relation is established between the problem of finding an equilibrium and of enlargement of filtrations. Random announcement time is random is also considered. In such a case the market is not fully efficient and there exists equilibrium if the sensitivity of prices with respect to the global demand is time decreasing according with the distribution of the random time. Second: Power variations. it is considered, the asymptotic behavior of the power variation of processes of the form _integral_0^t u(s-)dS(s), where S_ is an alpha-stable process with index of stability 0&alpha&2 and the integral is an Itô integral. Stable convergence of corresponding fluctuations is established. These results provide statistical tools to infer the process u from discrete observations. Third: A bond market is studied where short rates r(t) evolve as an integral of g(t-s)sigma(s) with respect to W(ds), where g and sigma are deterministic and W is the stochastic Wiener measure. Processes of this type are particular cases of ambit processes. These processes are in general not of the semimartingale kind.
Resumo:
The synthesis of three bidentate, hemilabile phosphine ligands, newly synthesized in the research group (TPOdiphos, DPPrPOdiphos and SODPdiphos), has been up-scaled and optimized. The ligand substitution reaction on Mo(CO)6 and W(CO)6 has been studied and the corresponding complexes fac-[MTPOdiphos(CO)3], fac-[MDPPrPOdiphos(CO)3], and fac-[MSODPdiphos(CO)3], (M= Mo, W) have been isolated in good yields and characterized by NMR, IR and HR MS. In the case of fac- [MoTPOdiphos(CO)3] the XRD crystal structure was resolved. The complexes were found to be octahedral, neutral molecules, with the metal in the zero oxidation state and the ligand adopting a facial P,P,O-coordination. The hard ligand atom (oxygen) is expected to exhibit special features the future applications of these novel ligands.