In a panel data model with random effects, when autocorrelation in the error is considered, (Gaussian) maximum likelihood estimation produces a dramatically large number of corner solutions: the variance of the random effect appears (incorrectly) to be zero, and a larger autocorrelation is (incorrectly) assigned to the idiosyncratic component. Thus heterogeneity could (incorrectly) be lost in applications to panel data with customarily available time dimension, even in a correctly specified model. The problem occurs in linear as well as nonlinear models. This article aims at pointing out how serious this problem can be (largely neglected by the panel data literature). A set of Monte Carlo experiments is conducted to highlight its relevance, and we explain this unpleasant effect showing that, along a direction, the expected log-likelihood is nearly flat. 相似文献
Why do estimates of the intergenerational persistence in earnings vary so much for the United States? Recent research suggests that lifecycle bias may be a major factor [Grawe, N., Lifecycle bias in estimates of intergenerational earnings persistence. Labour Economics 2006, 13:551–570; Haider, S., and Solon, G., Life-cycle variation in the association between current and lifetime earnings. American Economic Review 2006, 96(4):1308–1320.]. In this paper we estimate the intergenerational correlation in lifetime earnings by using sons' and fathers' earnings at similar ages in order to account for lifecycle bias. Our estimate based on earnings measured at 35–44 for both fathers and sons is similar to that for the age range 45–54. 相似文献
In this article we take further the debate on the ethics of competitive intelligence gathering, which until now has been very limited. Drawing on empirical research from a mobile telephone company in the United Kingdom, we present the case that while mystery shopping is not the worst activity in which an organization might be involved, it is basically unethical. Mystery shopping involves deception and the obtaining of competitive information under false pretences. Common arguments are that 'everyone is doing it' and that the information is in the public domain. Neither of these points convincingly justifies the requirement for an employer to ask an employee to lie and deceive others on behalf of the company. The use of students and those in low power positions in the organization is a further concern. 相似文献
The robust Russian economic recovery after the 1998 financial crisis raised the economic standing of the population, especially for lowly paid workers, most of whom are women. In this paper I use the Russian Longitudinal Monitoring Survey from 1996 through 2002 to ask whether this helped to reduce the gender wage gap. I first focus on those whose wages are paid in full. Next, I ask about the gender composition of wage arrears as the overall extent of wage arrears dropped from 60 to 20 per cent after the 1998 crisis. I show that a temporary widening of the overall gender wage gap in 2000 is due to low‐wage women becoming more likely to receive their wages in full than low‐wage men. Except for this effect, the male–female pay difference in Russia exhibits a stable pattern. 相似文献
We evaluate the effect of performance-based scholarship programs for post-secondary students on student time use and effort and whether these effects are different for students we hypothesize may be more or less responsive to incentives. To do so, we administered a time-use survey as part of a randomized experiment in which community college students in New York City were randomly assigned to be eligible for a performance-based scholarship or to a control group that was only eligible for the standard financial aid. This paper contributes to the literature by attempting to get inside the “black box” of how students respond to a monetary incentive to improve their educational attainment. We find that students eligible for a scholarship devoted more time to educational activities, increased the quality of effort toward and engagement with their studies, and allocated less time to leisure. Additional analyses suggest that students who were plausibly more myopic (place less weight on future benefits) were more responsive to the incentives, but we find no evidence that students who are arguably more time constrained were less responsive to the incentives.
A state of the Art trend analysis of the Library and Information science reveals that the Library world is in the midst of the technological restructuring. Every branch of library work changes continuously because of the technological facilities, although the missions and goals remain unaltered. The libraries belong to these professional divisions which involve the innovation and technology transfer in everyday life. In most of the cases innovation either as a product or as a procedure goes into the libraries, it's not a phenomenon produced by them.On the strategic level libraries on average have developed the ability to collect, process and assimilate technological innovation.On the organizational level libraries follow the changes which technology transfer dictates such as close co-operation with computer centers and external commercial information suppliers, software and hardware suppliers, science and technology achievements, etc. It is too common to libraries to develop routines and Best Practices for every task, derived by the technology they use, for the cost decrease, the time save and the increase of the effectiveness and efficiency.The innovative process is the kind which libraries could adopt, as innovation is composed of the systematic retrieve of changes and systematic analysis of the opportunities which these changes could contribute to economic and social improvement.Innovation above all, is a social procedure, as it is interpreted in terms such as creativity, desires, fantasy and the ability to take risks and to change. So innovation and technology transfer differentiates the role of the librarian and extends it beyond the limits of the information intermediary. The librarian in order to involve, anticipate and especially produce innovation has to learn how to learn, as libraries have to learn how to change.The presentation will be a methodological one and will focus on Best Practices, the definition and a short report, how they combine with the library functions and how they produce innovative processes and new Best Practices. An evaluation of Best Practices according the Value Analysis method is included as a prerequisite of the final choice of which practice is characterised as Best and which not. 相似文献
We develop a theory’ and empirical test of how the legal system affects the relationship between venture capitalists and entrepreneurs. The theory uses a double moral hazard framework to show how optimal contracts and investor actions depend on the quality of the legal system. The empirical evidence is based on a sample of European venture capital deals. The main results are that with better legal protection, investors give more non-contractible support and demand more downside protection. These predictions are supported by the empirical analysis. Using a new empirical approach of comparing two sets of fixed-effect regressions, we also find that the investor’s legal system is more important than that of the company in determining investor behavior. 相似文献