首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
借鉴Franses and Ghijsel[1](1999)和Charles and Darne[2](2005)提出的鉴别和校正金融序列加性异常值的方法,以GARCH模型为例,对我国的上证综合指数和深圳成分指数进行了加性异常值的鉴定与校正,并对校正后的残差进行了正态检验。结果表明该方法效果显著,进行异常值校正后的GARCH(1,1),更好地拟合金融时间序列中的尖峰厚尾和波动丛聚性的特性,纠正了正态分布的GARCH(1,1)对时间序列拟合的偏误。  相似文献   

2.
The paper develops a novel testing procedure for hypotheses on deterministic trends in a multivariate trend stationary model. The trends are estimated by the OLS estimator and the long run variance (LRV) matrix is estimated by a series type estimator with carefully selected basis functions. Regardless of whether the number of basis functions K is fixed or grows with the sample size, the Wald statistic converges to a standard distribution. It is shown that critical values from the fixed-K asymptotics are second-order correct under the large-K asymptotics. A new practical approach is proposed to select K that addresses the central concern of hypothesis testing: the selected smoothing parameter is testing-optimal in that it minimizes the type II error while controlling for the type I error. Simulations indicate that the new test is as accurate in size as the nonstandard test of Vogelsang and Franses (2005) and as powerful as the corresponding Wald test based on the large-K asymptotics. The new test therefore combines the advantages of the nonstandard test and the standard Wald test while avoiding their main disadvantages (power loss and size distortion, respectively).  相似文献   

3.
A number of topics are discussed concerning how economic forecasts can be improved in quality or at least in presentation. These include the following: using 50% uncertainty intervals rather than 95%; noting that even though forecasters use many different techniques, they are all occasionally incorrect in the same direction; that there is a tendency to underestimate changes; that some expectations and recently available data are used insufficiently; lagged forecasts errors can help compensate for structural breaks; series that are more forecastable could be emphasized and that present methods of evaluating forecasts do not capture the useful properties of some methods compared to alternatives.  相似文献   

4.
Rationalizing non‐participation as a resource deficiency in the household, this paper identifies strategies for milk‐market development in the Ethiopian highlands. The additional amounts of covariates required for positive marketable surplus—‘distances‐to market’—are computed from a model in which production and sales are correlated; sales are left‐censored at some unobserved threshold; production efficiencies are heterogeneous; and the data are in the form of a panel. Incorporating these features into the modeling exercise is important because they are fundamental to the data‐generating environment. There are four reasons. First, because production and sales decisions are enacted within the same household, both decisions are affected by the same exogenous shocks, and production and sales are therefore likely to be correlated. Second, because selling involves time and time is arguably the most important resource available to a subsistence household, the minimum sales amount is not zero but, rather, some unobserved threshold that lies beyond zero. Third, the potential existence of heterogeneous abilities in management, ones that lie latent from the econometrician's perspective, suggest that production efficiencies should be permitted to vary across households. Fourth, we observe a single set of households during multiple visits in a single production year. The results convey clearly that institutional and production innovations alone are insufficient to encourage participation. Market‐precipitating innovation requires complementary inputs, especially improvements in human capital and reductions in risk. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

5.
In this paper we assess overall accuracy in survey self-reports on giving to charitable organizations, direction of bias in self-reports, and the influence of this bias on relationships. We compare donations to one specific health charity reported in the Giving in the Netherlands Panel Study 2003 with donations recorded in the database (n =  191). We find that (a) reported donations are significantly higher than recorded donations; (b) reported amounts contributed are correlated very strongly with recorded contributions; (c) differences between amounts reported and amounts recorded are positively related to education, religious affiliation, and the tendency to social desirability, and negatively to household income. This suggests that effects of education are overestimated and effects of income and religious affiliation are underestimated using self-reports on donations rather than archival records.  相似文献   

6.
This article shows that spurious regression results can occur for a fixed effects model with weak time series variation in the regressor and/or strong time series variation in the regression errors when the first‐differenced and Within‐OLS estimators are used. Asymptotic properties of these estimators and the related t‐tests and model selection criteria are studied by sending the number of cross‐sectional observations to infinity. This article shows that the first‐differenced and Within‐OLS estimators diverge in probability, that the related t‐tests are inconsistent, that R2s converge to zero in probability and that AIC and BIC diverge to ?∞ in probability. The results of the article warn that one should not jump to the use of fixed effects regressions without considering the degree of time series variations in the data.  相似文献   

7.
Abstract Survey data on Eastern Europe is investigated with respect to two major questions: How do people view the creation of a market economy and how do they assess the speed of economic transformation and privatization. These questions are analyzed by looking at the development over 1990 to 1992 and by performing regressions with a number of demographic variables as regressors. Some findings are that the opposition to the creation of a market economy is increasing over time, that in Hungary and Poland people are quite satisfied with the speed of transformation as compared to Czechs and Slovaks, that the Polish are divided over the speed of privatization, and that the relationship between the speed of transformation and privatization is not considered to be very tight by the respondents.  相似文献   

8.
This paper examines trends in allocative efficiency over the period 1960–1961 to 1986–1987 in seven Indian industries, namely refining and manufacture of sugar; petroleum refining; manufacture of chemicals, fertilizers and pesticides locomotives and parts, locomotives, and cotton textiles. We discover that allocative inefficiency has been non zero in each industry for every year. Allocative inefficiency has not declined over time in those industries where prices are administered, whereas in industries where prices are not administered it has. Industries that are predominantly in the public sector are not necessarily characterized by greater allocative inefficiency than those that are predominantly in the private sector.  相似文献   

9.
We provide specific qualifications in order that Kuhn–Tucker type Euler equations and transversality conditions at infinity hold in stochastic equilibrium models with heterogeneous agents and where assets are traded in sequential markets. It is not assumed that uncertainty is modeled as an event-tree structure or that preferences are necessarily bounded. We also describe an important class of preferences based on bounded relative risk aversion which yields relevant simplifications. Our results are used to establish conditions that rule out asset pricing bubbles. Specific examples of economies with bubbles are also discussed. Received: 28 January 2002 / Accepted: 19 July 2002 We are grateful to the editor and an anonymous referee for their valuable comments. This research was partially supported by MURST (Italy), National Group on “Nonlinear Dynamics and Stochastic Models in Economics and Finance”.  相似文献   

10.
The stability and efficiency of directed communication networks   总被引:5,自引:0,他引:5  
Abstract. This paper analyzes the formation of directed networks where self-interested individuals choose with whom they communicate. The focus of the paper is on whether the incentives of individuals to add or sever links will lead them to form networks that are efficient from a societal viewpoint. It is shown that for some contexts, to reconcile efficiency with individual incentives, benefits must either be redistributed in ways depending on “outsiders” who do not contribute to the productive value of the network, or in ways that violate equity (i.e., anonymity). It is also shown that there are interesting contexts for which it is possible to ensure that efficient networks are individually stable via (re)distributions that are balanced across components of the network, anonymous, and independent of the connections of non-contributing outsiders.  相似文献   

11.
We focus on how interpersonal characteristics should influence leader support for gender equity in organizations. Recognizing gender disparities in organizations and the “labyrinth” that women face when they advance in their careers (cf. Eagly & Carli, 2007), we develop a model for how interpersonal characteristics of leaders, both men and women, influence power construal and thus their use of empowerment, mentoring, and performance feedback, ultimately affecting career opportunities for women in organizations. The model proposes that leaders who are high on communal goal orientation, a prosocial characteristic, are more likely to construe power through a responsibility lens and behave in ways that ultimately support gender equity in organizations. In contrast, leaders with an exchange goal orientation are more likely to construe power through a freedom lens and behave in ways that are self-serving. Prestige motivation will increase the extent to which leaders, especially those who are communally oriented, share power. Dominance motivation will increase the extent to which leaders, especially those who are exchange oriented, act in self-interest and retain power, ultimately imposing barriers to women's career advancement. Organizations can potentially increase leader power sharing by encouraging and reinforcing leaders' prosocial characteristics of communal orientation and prestige motivation. Implications for research and practice are discussed.  相似文献   

12.
While the use of real effective exchange rates in stationarity tests of purchasing power parity (PPP) avoids the problems created using bilateral rates, these rates are often constructed using trade shares that are fixed at a single base year. This method fails to take into account the fact that trade shares can change drastically in parts of the world that are undergoing dramatic transformations. In this study, we apply linear as well as nonlinear stationarity tests to 52 currencies’ real effective rates, which were constructed using time-varying weights. Incorporating a time trend, we are also able to assess whether breakdowns in PPP are due to productivity differentials. We find that while nonlinear tests provide more evidence of “productivity bias” than do linear tests, they do not provide much more evidence of PPP. A comparison to a previous study that used fixed-weight data shows that there is somewhat more evidence of productivity bias using the new dataset, especially in Eastern Europe and Asia. We can conclude that PPP and a key cause of its breakdown are somewhat sensitive to the use of time-varying weights in these stationarity tests.  相似文献   

13.
Summary Lehmann [p. 83] has shown that some families of probability measures with monotone likelihood ratios (m.l.r.) admit median unbiased estimates which are optimum in the sense that among all median unbiased estimates they minimize the expected loss for any loss function which assumes its minimal value zero for the “true” parameter value and is nondecreasing as the parameter moves away from the true value in either direction. This very strong optimum property was proved under the assumption that all probability measures of the m.l.r.-family have continuous distribution functions, that they are mutually absolutely continuous and that each element of the support is the median of somep-measure of the family. This result does therefore not cover important cases such as the binomial families or thePoisson family. The purpose of the present paper is to show the existence ofrandomized median unbiased estimates with the same optimum property for m.l.r.-families which are closed and connected with respect to the strong topology. Such families are always dominated. We do, however, neither assume that thep-measures are mutually absolutely continuous nor that the distribution functions are continuous. We remark that the use of randomized estimates is indispensable here because nonrandomized median unbiased estimates do not always exist in the general case.  相似文献   

14.
Abstract

This paper examines the relationship between the breadth and depth of cultural exposure (CE), intercultural sensitivity and intercultural competence to draw implications that can improve recruitment and staff development practices in organizations with a culturally diverse workforce. Findings from a survey (N = 214) in Australia support the notion that intercultural competence is a broader concept that requires a deep exposure to other cultures as compared to intercultural sensitivity. The findings suggest that breadth of CE has limited potential whereas depth of CE is more beneficial in improving an individual’s intercultural abilities. Implications are drawn based on the findings of the study such that organizations are able to recruit and develop employees who are truly interculturally inclined and can effectively navigate the challenges of working in today’s multicultural organizations.  相似文献   

15.
Journal rankings are important for a variety of reasons, most importantly as the basis of academic tenure and promotion decisions. A common approach in other fields is the citations methodology which is used in this study to determine the relative importance of various operations management (OM) journals. The citations analysis noted the frequency that all other journals are cited in Decision Sciences, Journal of Operations Management, and Management Science during the period 1992 to 1994. Rankings are provided based on total citations, citations per article, and citations per words published. The study shows that the journals with the most importance to OM research are Management Science, Decisions Sciences and Operations Research. Other journals important to OM research are the Harvard Business Review, Journal of Operations Management, and IIE Transactions.  相似文献   

16.
M. Budde 《Metrika》1984,31(1):203-213
Summary Williams-designs are proved to be optimal within the class of latin 4×4-squares in rowcolumn-models, where serial correlations are fitted with an autoregressive scheme of first order.Designs are presented that are not generalized Youden-designs and that are better than Williams-designs for strong negative correlations. However, it will be shown that optimal designs do not depend on the special structure of the error covariance in models with only two columns and in models with a completely symmetric covariance matrix.  相似文献   

17.
Using state administrative records matched to the 1984 Survey of Income and Program Participation, we examine intertemporal relationships in response errors. False negative errors in reporting food stamps are highly correlated across interviews for the same household. Hypotheses that the error process can be explained by learning behaviour are not supported. Bivariate probit of response error in two periods reveals that responses to covariates are stable over time and the latent error terms are positively correlated. These findings support the hypothesis that respondents have a latent tendency to cooperate (or not cooperate) with surveys. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

18.
19.
abstract Two major perspectives can be construed in the literature concerning the nature of family owned businesses (FOBs). The first implies that these enterprises have unique characteristics of stewardship. FOB owners are said to care deeply about the long‐term prospects of the business, in large part because their family's fortune, reputation and future are at stake. Their stewardship is said to be manifested by unusual devotion to the continuity of the company, by more assiduous nurturing of a community of employees, and by seeking out closer connections with customers to sustain the business. The second perspective is less flattering. It proposes that FOBs are unusually subject to stagnation: they are said to face unique resource restrictions, embrace conservative strategies, eschew growth, and be doomed to short lives. This paper develops and examines the merits of the two perspectives, neither of which has been systematically articulated or researched. It does so in an empirical study of only small firms that are owned and managed by their founder. Within this sample, it compares firms that are FOBs, that is, family owned and managed, with non‐FOBs, that is, owned and managed by a founder with no other relative involved in the business. The findings show significant support for all three aspects of the stewardship perspective of FOBs, and no support for any elements of the stagnation perspective.  相似文献   

20.
Critics of Pope Francis’s Evangelii gaudium argue that recent economic growth and reductions in inequality are evidence that his notion of the “economy of exclusion” is misguided. However, Francis alludes to another type of exclusion—increased uncertainty generated by technological change that affects citizens even in developed nations. Drawing from Post‐Keynesian institutionalist theory, this article argues that this condition is common in capitalism, and that grassroots reforms are needed to ensure shared prosperity.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号