997 resultados para empirical likelihood


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This paper introduces new results obtained from a statistical investigation into a 3071-observation data set collected from a Vietnamese nationwide entrepreneurship survey. From established relationships, such factors as preparedness, financial resources and participation in social networks are confirmed to have significant effects on entrepreneurial decisions. Entrepreneurs, both financially constrained and unconstrained, who have a business plan tend to start their entrepreneurial ventures earlier. Also, financial constraints have a profound impact on the entrepreneurial decisions. When perceiving the likelihood of success to be high, an entrepreneur shows the tendency for prompt action on business ideas. But when seeing the risk of prolonging the waiting time to first revenue, a prospective entrepreneur would be more likely to wait for more favorable conditions despite the vagueness of "favorable". Additionally, empirical computations indicate that there is a 41.3% probability that an extant entrepreneur who is generating revenue sees high chance of success. Past work and entrepreneurial experiences also have positive impacts on both the entrepreneurial decisions and perceived chance of success.

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Biosignal measurement and processing is increasingly being deployed in ambulatory situations particularly in connected health applications. Such an environment dramatically increases the likelihood of artifacts which can occlude features of interest and reduce the quality of information available in the signal. If multichannel recordings are available for a given signal source, then there are currently a considerable range of methods which can suppress or in some cases remove the distorting effect of such artifacts. There are, however, considerably fewer techniques available if only a single-channel measurement is available and yet single-channel measurements are important where minimal instrumentation complexity is required. This paper describes a novel artifact removal technique for use in such a context. The technique known as ensemble empirical mode decomposition with canonical correlation analysis (EEMD-CCA) is capable of operating on single-channel measurements. The EEMD technique is first used to decompose the single-channel signal into a multidimensional signal. The CCA technique is then employed to isolate the artifact components from the underlying signal using second-order statistics. The new technique is tested against the currently available wavelet denoising and EEMD-ICA techniques using both electroencephalography and functional near-infrared spectroscopy data and is shown to produce significantly improved results. © 1964-2012 IEEE.

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In a Bayesian learning setting, the posterior distribution of a predictive model arises from a trade-off between its prior distribution and the conditional likelihood of observed data. Such distribution functions usually rely on additional hyperparameters which need to be tuned in order to achieve optimum predictive performance; this operation can be efficiently performed in an Empirical Bayes fashion by maximizing the posterior marginal likelihood of the observed data. Since the score function of this optimization problem is in general characterized by the presence of local optima, it is necessary to resort to global optimization strategies, which require a large number of function evaluations. Given that the evaluation is usually computationally intensive and badly scaled with respect to the dataset size, the maximum number of observations that can be treated simultaneously is quite limited. In this paper, we consider the case of hyperparameter tuning in Gaussian process regression. A straightforward implementation of the posterior log-likelihood for this model requires O(N^3) operations for every iteration of the optimization procedure, where N is the number of examples in the input dataset. We derive a novel set of identities that allow, after an initial overhead of O(N^3), the evaluation of the score function, as well as the Jacobian and Hessian matrices, in O(N) operations. We prove how the proposed identities, that follow from the eigendecomposition of the kernel matrix, yield a reduction of several orders of magnitude in the computation time for the hyperparameter optimization problem. Notably, the proposed solution provides computational advantages even with respect to state of the art approximations that rely on sparse kernel matrices.

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This paper examines the nature of monetary policy decisions in Mexico using discrete choice models applied to the Central Bank's explicit monetary policy instrument. We find that monetary policy adjustments in Mexico have been strongly consistent with the CB's inflation targeting strategy. We also find evidence that monetary policy responds in a forward-looking manner to deviations of inflation from the target and that observed policy adjustments exhibit asymmetric features, with stronger responses to positive than to negative deviations of inflation from the target and a greater likelihood of policy persistence during periods when monetary policy is tightened, compared with periods when policy is loosened.

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The paper studies what drives firms to voluntary delist from capital markets and what differs in firms’ behavior and fundamentals between public-to-private transactions and M&A deals with listed corporations. Moreover, I study the relationship between ownership percentage in controlling shareholders’ hands and cumulative returns around the delisting public announcement. I perform my tests both for the Italian and the US markets and I compare the findings to better understand how the phenomenon works in these different institutional environments. Consistent with my expectations, I find that the likelihood of delisting is mainly related to size, underperformance and undervaluation, while shareholders are more rewarded when their companies are involved in PTP transactions than in M&As with public firms.

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This paper tests the predictions of the Barro-Gordon model using US data on inflation and unemployment. To that end, it constructs a general game-theoretical model with asymmetric preferences that nests the Barro-Gordon model and a version of Cukierman’s model as special cases. Likelihood Ratio tests indicate that the restriction imposed by the Barro-Gordon model is rejected by the data but the one imposed by the version of Cukierman’s model is not. Reduced-form estimates are consistent with the view that the Federal Reserve weights more heavily positive than negative unemployment deviations from the expected natural rate.

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We examine whether and under what circumstances World Bank and International Monetary Fund (IMF) programs affect the likelihood of major government crises. We find that crises are, on average, more likely as a consequence of World Bank programs. We also find that governments face an increasing risk of entering a crisis when they remain under an IMF or World Bank arrangement once the economy's performance improves. The international financial institution's (IFI) scapegoat function thus seems to lose its value when the need for financial support is less urgent. While the probability of a crisis increases when a government turns to the IFIs, programs inherited by preceding governments do not affect the probability of a crisis. This is in line with two interpretations. First, the conclusion of IFI programs can signal the government's incompetence, and second, governments that inherit programs might be less likely to implement program conditions agreed to by their predecessors.

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The Birnbaum-Saunders regression model is becoming increasingly popular in lifetime analyses and reliability studies. In this model, the signed likelihood ratio statistic provides the basis for testing inference and construction of confidence limits for a single parameter of interest. We focus on the small sample case, where the standard normal distribution gives a poor approximation to the true distribution of the statistic. We derive three adjusted signed likelihood ratio statistics that lead to very accurate inference even for very small samples. Two empirical applications are presented. (C) 2010 Elsevier B.V. All rights reserved.

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The Birnbaum-Saunders regression model is commonly used in reliability studies. We address the issue of performing inference in this class of models when the number of observations is small. Our simulation results suggest that the likelihood ratio test tends to be liberal when the sample size is small. We obtain a correction factor which reduces the size distortion of the test. Also, we consider a parametric bootstrap scheme to obtain improved critical values and improved p-values for the likelihood ratio test. The numerical results show that the modified tests are more reliable in finite samples than the usual likelihood ratio test. We also present an empirical application. (C) 2009 Elsevier B.V. All rights reserved.

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This project aimed to conceptualise and analyse empirically the antecedents of word-of-mouth in the context of an infrequently purchased service (tourism special events). The relationships examined included those between involvement, past experience, overall satisfaction, interest in attending next time, likelihood of attending next time, and the likelihood of recommending to others that they attend the event. There was some support for the overall model, in that the regressing of likelihood of recommending on the other variables produced an equation containing measures of most of the key variables, viz., revisit intention, satisfaction, revisit interest, and involvement. However, involvement appeared to operate in the opposite direction to that hypothesised.

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The aims of this research were to examine the relationships between customer satisfaction, customer complaint behaviour, service recovery and the intention to repurchase in the Australian Pay TV industry. A survey of 171 respondents suggested that overall customer satisfaction was the main driver of the likelihood of disconnection from the Pay TV service. Those respondents who reported having a problem but not complaining directly about it were significantly more likely to have the intention to disconnect in the future than those who complained directly to their Pay TV service provider. However, there was no significant difference in terms of perceptions of overall satisfaction between those who had a problem and complained and those who had a problem and chose not to complain.

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This paper reports on a survey of lapsed members of an Australian professional National Rugby League (NRL) Club. Analysis of the 195 useable responses returned suggest that these lapsed members had originally joined as much for intangible aspects, such as seeking a greater level of involvement with the club, as for the functional aspects such as savings on game entry. Overall, these lapsed members were satisfied with the service they received whilst a member, and claimed it had been performed in line with expectations. The main drivers of satisfaction were also a mix of tangible and intangible factors such as feeling valued by the club and receiving discounts on entry costs. The members gave a number of reasons for not rejoining in 2002, but primarily cited an inability to attend games. Despite joining for intangible reasons, it seems that if these members could not get to games, they perceived that membership was not worth maintaining. That said, a large number of members indicated that as their circumstances change they will rejoin the club, supporting the theory that non-renewal is not driven by service failure, but rather the perception that attendance is still the core product (entertainment). The overall level of satisfaction had a weak but positive relationship with the likelihood of members rejoining in the future.

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The role of marketing employees in contributing to marketing performance (individual and organisational), has, in general, been under-researched. Most research in marketing has focused on the activities of marketing employees and the outputs of those activities, rather than the inputs, i.e., the abilities, skills, or knowledge of the marketing employees themselves. This study represents a unique insight into the marketing capabilities and marketing performance of employees within a multinational organisation, as reported by the employees themselves. Using Structural Equation Modelling (SEM), strong support was found for a systems model of marketing competency marketing performance, suggesting that such relationships are complex and are not studied readily in isolation from external factors. Organisations that are able to conceptualise, operationalise, measure, monitor, and address marketing employee competency, intentions, and perceptions, as well as maintain the appropriate levels of management control, should have a greater likelihood of creating high performing employees, than those organisations that are unable to focus on these core aspects of people's performance. In addition, those same employees are likely to be more satisfied, motivated, and committed, require less assistance and time to complete tasks, and have greater productivity and be less likely to leave the orga.'1isation.

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There is considerable evidence to suggest that consumer dissatisfaction with self-service technologies is widespread. However, there has been little conceptual or empirical scrutiny of the likelihood that consumers will complain to an organization (likelihood of voice) in this context. This study contributes to the service domain by testing empirically a model of the antecedents of consumers' likelihood of voice in unsatisfactory encounters with self-service technologies. A model is tested that combines established antecedents of voice, such as likelihood of voice success, and those that have not yet been considered, including self-service technology powerlessness and need to vent. The results support the proposed model in general. Theoretical and managerial implications of the findings are discussed.

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This paper develops and tests a model to predict small and medium enterprise (SME) financial distress based on empirical evidence from Thailand. A sample comprising 198 financial statements of non-financially distressed and 68 statements of financially distressed SMEs were used. A parametric t-test was conducted to establish differences between financial characteristics of the two groups of SMEs.

Results show statistically significant differences (t values significant at .001) between the two groups of SMEs in the financial ratios used for the study. Discriminant analysis was then conducted to develop a model for predicting the likelihood of an SME experiencing financial distress.

The model hits an accuracy level of 97%, which compares favourably with the probability of accurate classification by chance (i.e., 65% after adjusting for the unequal sample sizes of the two groups of SMEs). A test of the model with a new sample shows the validity of the model beyond the original sample, confirming that Thai SME financial distress is amenable to prediction to a statistically significant extent. The model is expected to serve SME managers and creditors in assessing financial health of SMEs before making important decisions. The results are also expected to inform policymakers in formulating economic policies concerning SMEs.