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131.
Milk quota trading rules differ across EU member countries. In Denmark a biannual milk quota exchange was set up in 1997 to promote a more efficient reallocation of milk quotas as well as to reduce transaction costs related to the searching and matching of sellers and buyers. Using two comprehensive unbalanced panel data sets on organic and conventional milk farms this study attempts to disentangle the effects of the introduction of quota transferability on the production structure of those farms as well as the probability of market entry/exit. Bayesian estimation techniques are used to estimate an input oriented generalized Leontief distance function as well as a curvature constrained specification. The results suggest that the deregulation in the quota allocation mechanism led to an increased allocative efficiency of organic as well as conventional milk production as well as a relative shift of the PPF in favor of the production of organic milk.  相似文献   
132.
We present and test a method for computing risk-minimizing static hedge strategies. The method is straightforward, yet flexible with respect to the type of contingent claim being hedged, the underlying asset dynamics, and the choice of risk-measure and hedge instruments. Extensive numerical comparisons for barrier options in a model with stochastic volatility and jumps show that the resulting hedges outperform previous suggestions in the literature. We also demonstrate that the risk-minimizing static hedges work in an infinite intensity Levy-driven model, and a number of controlled experiments illustrate that hedge performance is robust to model risk.  相似文献   
133.
This paper reports industry concentration measures for the South African manufacturing sector over the 1972–1996 period for the three digit industry classification. Noted are high level of industry concentration in South African manufacturing, and a rising trend in concentration across a wide range of industries as measured by the Gini coefficient, though some countervailing evidence emerges on the Rosenbluth index. Analytically the paper examines the impact of concentration on employment and investment rates. Results show that increased concentration unambiguously lowers employment. For investment rates, increased inequality of market share serves to raise investment rates, while falling firm numbers for any given inequality of market share lowers investment rates. The difference is consistent with a disciplining effect of a competitive fringe of firms on the behaviour of large firms in a market.  相似文献   
134.
This paper develops a pure simulation-based approach for computing maximum likelihood estimates in latent state variable models using Markov Chain Monte Carlo methods (MCMC). Our MCMC algorithm simultaneously evaluates and optimizes the likelihood function without resorting to gradient methods. The approach relies on data augmentation, with insights similar to simulated annealing and evolutionary Monte Carlo algorithms. We prove a limit theorem in the degree of data augmentation and use this to provide standard errors and convergence diagnostics. The resulting estimator inherits the sampling asymptotic properties of maximum likelihood. We demonstrate the approach on two latent state models central to financial econometrics: a stochastic volatility and a multivariate jump-diffusion models. We find that convergence to the MLE is fast, requiring only a small degree of augmentation.  相似文献   
135.
This paper presents time series on South African tertiary education.The data series presented cover inputs and outputs for the university,technical training and teacher training systems. Modern growththeory has emphasised the importance of human capital, thoughempirical studies have attempted to isolate human capital impactsthrough single aggregate measures that capture only a quantityof human capital dimension. While data analysis in the presentstudy is exploratory in nature, we show that strong qualitydifferentials exist both within and between different partsof the tertiary education system. The methodological implicationfor growth studies is that fully accounting for both the quantityand quality of human capital in aggregate human capital measuresthus faces significant measurement difficulties. The data alsoestablish that discrimination in the South African tertiaryeducation was not simply a question of underresourcing of Blackinstitutions. Quality of output was low, but attaining it wasfrequently very expensive.  相似文献   
136.
Perfectly discriminating contests (all pay auctions) are widely used as a model of situations where individuals devote resources to win some prize. In reality such contests are often preceded by investments of the contestants into their ability to fight in the contest. This paper studies a two stage game where in the first stage, players can invest to lower their bid cost in a perfectly discriminating contest, which is played in the second stage. Different assumptions on the timing of investment are studied. With simultaneous investments, equilibria in which players play a pure strategy in the investment stage are asymmetric, exhibit incomplete rent dissipation, and expected effort is reduced relative to the game without investment. There also are symmetric mixed strategy equilibria with complete rent dissipation. With sequential investment, the first mover always invests enough to deter the second mover from investing, and enjoys a first mover advantage. I also look at unobservable investments and endogenous timing of investments. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
137.
We estimated a normalized translog yield-response model using African farm-household survey data to compare the yield of smallholder maize production under integrated soil fertility management (ISFM) and chemical-based soil fertility management. Controlling for other factors, maize yield responses were higher under ISFM. Results suggest ISFM practices would significantly improve the profitability of smallholder maize production, especially under escalating fertilizer prices.  相似文献   
138.
Extending previous research on celebrity endorsements, the study investigates whether the meaning of celebrities is transferred to endorsed brands and how transfer effects develop over time. Additionally, the moderating roles of brand experience, celebrity liking, and consumers’ age are investigated. The hypothesized effects are modeled using a propositional learning approach with an experimental repeated-measures design (panel data). Results confirm the assumed meaning transfer effect. In addition, the effects appear to be substantially stronger after about a week indicating some type of sleeper effect. Furthermore, the effects increase with increasing brand experience and celebrity liking. Adolescent consumers are not differently affected when compared to adults and controlled for the differing levels of brand experience. Results are discussed in light of propositional learning theory. Future areas of research are proposed.  相似文献   
139.
abstract It is crucial from an employee's point of view to perceive some degree of stability even in times of major organizational change. This paper examines the role of a sense of continuity for organizational identification after an organizational merger. We argue that mergers and acquisitions so often end in failures partly because the change is designed in discontinuous ways and employees do not feel they are doing the same job after the merger as before. Such discontinuous change engenders a critical tension between positive and negative effects of identification that has not yet been fully understood. To deepen the understanding of this tension, in‐depth interviews were conducted in a recently merged German industrial company. Based on these qualitative data we demonstrate how features of the post‐merger company structure and the way it was implemented may have eroded organizational identification. Finally, we propose a parsimonious model to be tested by future research, in which the sense of continuity is consisting of both observable as well as projected continuity.  相似文献   
140.
The Impact of Jumps in Volatility and Returns   总被引:17,自引:0,他引:17  
This paper examines continuous‐time stochastic volatility models incorporating jumps in returns and volatility. We develop a likelihood‐based estimation strategy and provide estimates of parameters, spot volatility, jump times, and jump sizes using S&P 500 and Nasdaq 100 index returns. Estimates of jump times, jump sizes, and volatility are particularly useful for identifying the effects of these factors during periods of market stress, such as those in 1987, 1997, and 1998. Using formal and informal diagnostics, we find strong evidence for jumps in volatility and jumps in returns. Finally, we study how these factors and estimation risk impact option pricing.  相似文献   
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