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91.
We extend the class of dynamic factor yield curve models in order to include macroeconomic factors. Our work benefits from recent developments in the dynamic factor literature related to the extraction of the common factors from a large panel of macroeconomic series and the estimation of the parameters in the model. We include these factors in a dynamic factor model for the yield curve, in which we model the salient structure of the yield curve by imposing smoothness restrictions on the yield factor loadings via cubic spline functions. We carry out a likelihood-based analysis in which we jointly consider a factor model for the yield curve, a factor model for the macroeconomic series, and their dynamic interactions with the latent dynamic factors. We illustrate the methodology by forecasting the U.S. term structure of interest rates. For this empirical study, we use a monthly time series panel of unsmoothed Fama–Bliss zero yields for treasuries of different maturities between 1970 and 2009, which we combine with a macro panel of 110 series over the same sample period. We show that the relationship between the macroeconomic factors and the yield curve data has an intuitive interpretation, and that there is interdependence between the yield and macroeconomic factors. Finally, we perform an extensive out-of-sample forecasting study. Our main conclusion is that macroeconomic variables can lead to more accurate yield curve forecasts.  相似文献   
92.
Asian options are securities with a payoff that depends on the average of the underlying stock price over a certain time interval. We identify three natural assets that appear in pricing of the Asian options, namely a stock S, a zero coupon bond BT with maturity T, and an abstract asset A (an “average asset”) that pays off a weighted average of the stock price number of units of a dollar at time T. It turns out that each of these assets has its own martingale measure, allowing us to obtain Black–Scholes type formulas for the fixed strike and the floating strike Asian options. The model independent formulas are analogous to the Black–Scholes formula for the plain vanilla options; they are expressed in terms of probabilities under the corresponding martingale measures that the Asian option will end up in the money. Computation of these probabilities is relevant for hedging. In contrast to the plain vanilla options, the probabilities for the Asian options do not admit a simple closed form solution. However, we show that it is possible to obtain the numerical values in the geometric Brownian motion model efficiently, either by solving a partial differential equation numerically, or by computing the Laplace transform. Models with stochastic volatility or pure jump models can be also priced within the Black–Scholes framework for the Asian options.  相似文献   
93.
Previous research on the influence of accompanying expatriate spouses has emphasized the negative impact on the business expatriates that could contribute to unsuccessful outcomes of the foreign assignments. But spouses’ influences could also be positive. Applying ethnographic field-work methodology, this study investigated female spouses’ involvement in the career of a sample of Danish business expatriates living in the same compound in Saudi Arabia. Results showed that the accompanying partners were active in trying to support and further their expatriate husbands’ immediate careers and repatriation opportunities by using social strategies, such as creating alliances and establishing social networks with influential others through social contacts and dinner parties. The female trailing partners also tried as a group to influence company decisions regarding working schedules, pay, and holidays. These findings are consistent with recent theoretical developments focusing on positive outcomes of the work–family interface and social capital theory and are in line with empirical research on repatriation and post-assignment careers.  相似文献   
94.
We consider the portfolio choice problem for a long‐run investor in a general continuous semimartingale model. We combine the decision criterion of pathwise growth optimality with a flexible specification of attitude toward risk, encoded by a linear drawdown constraint imposed on admissible wealth processes. We define the constrained numéraire property through the notion of expected relative return and prove that drawdown‐constrained numéraire portfolio exists and is unique, but may depend on the investment horizon. However, when sampled at the times of its maximum and asymptotically as the time‐horizon becomes distant, the drawdown‐constrained numéraire portfolio is given explicitly through a model‐independent transformation of the unconstrained numéraire portfolio. The asymptotically growth‐optimal strategy is obtained as limit of numéraire strategies on finite horizons.  相似文献   
95.
Although the core of most services is a person-to-person encounter, we still know very little about its underlying mechanisms as very few models or theories have been developed for these dynamic interactions between persons. An holistic approach to quality improvement is therefore suggested. Different prototypical person-to-person encounters may be studied on different levels and interfaces in service operations to eliminate inconsistencies. The aim of this contribution is to review some recent research findings for person-to-person encounters from the neighbouring management fields of services, operations and human resources in order to draw together their strategic implications for service managers. Some ontological and methodological considerations of studying person-to-person encounters from a qualitative perspective are discussed. The outline of a multi-disciplinary and learning-centred research approach is also suggested. Findings are integrated by a model of four generic and strategic processes for quality improvement in service operations. Finally, some implications for managers are proposed.  相似文献   
96.
Zimmer (‘The role of copulas in the housing crisis’, Review of Economics and Statistics 2012; 94 : 607–620) provides an interesting case study of the pitfalls of using parametric copulas to understand the US housing crisis in the latter part of 2000s. The original study by Zimmer (2012) employs a finite‐mixture copula to illustrate that the symmetry of the Gaussian copula may not be tenable, especially for US housing price data during the time period from 1975:Q2 to 2009:Q1. We undertake a replication of his study in a wide sense. First, we replicate the study by incorporating revised data and then extending the dataset to include the most recent data. Second, we implement a nonparametric copula estimator recently proposed by Racine (‘Mixed data kernel copulas’, Empirical Economics forthcoming) to the parametrically filtered data used in Zimmer (2012). Our replication finds that the application of the nonparametric copula to the same and extended filtered data provides an alternative flexible specification for copulas. However, the overall cautionary message of the flexible‐form copula espoused in Zimmer (2012) remains. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
97.
Research on the organization of innovation projects suggests that increased project flexibility is a common reaction to high levels of technological turbulence. However, existing definitions of project flexibility are inconsistent and sometimes unclear, and empirical evidence is limited. This article makes an important distinction between flexible project planning and flexible project specifications. A negative relationship is found between flexible project planning and innovation project performance, whereas flexible product specifications are found to contribute positively.This article also examines how technological turbulence contributes to the choice of flexible or inflexible strategies. Technological turbulence can be present in the external environment or can be internal to the firm, when radically new products are developed. The findings suggest that when businesses perceive technological turbulence in the environment they are more likely to adopt flexible approaches to innovation in an attempt to adapt to external pressures. In technologically innovative projects, product specifications are likely to remain fixed while project organization is likely to be adapted to the needs of the project.Taken together, the findings suggest that innovation projects should maintain stable organization, schedules and budgets, but stay flexible about product specifications. Vigilance with regards to external and internal conditions of technological turbulence, which may lead organizations to be more flexible in terms of project planning, is needed.  相似文献   
98.
Students of immigrant entrepreneurship show a distinct preference for ethnic concentrations. They focus on small entrepreneurship in sectors with large concentrations of immigrant businesses or on ethnic commercial precincts. This preference stems from practical and theoretical considerations. It seems that the study of such concentrations, or niches, is essential to the theoretical understanding of the structural determinants of small entrepreneurship and the processes of economic incorporation of immigrants. This paper challenges this orthodoxy. It argues that it is important to assess the factors and processes that positively and negatively affect the formation of niches. This argument is corroborated by an analysis of the construction industry in the Netherlands. According to Waldinger (1995: 577), ‘construction represents the quintessential ethnic niche’, but immigrants in the Netherlands did not carve out a niche. This exceptional situation can be attributed to a sector-specific configuration of social, economic and institutional processes.  相似文献   
99.
In the assessment of mortality and morbidity risk, the ability of family history and genetic test results to predict the age of occurrence, severity, and long-term prognosis of 'genetic' diseases is important. An increasing number of gene-gene and gene-environment interactions have been demonstrated in a number of monogenic Mendelian diseases. These interactions can significantly modify the clinical presentation (disease phenotype) of diseases previously regarded purely as 'genetic.' As a result, 'genetic' diseases can be positioned in a continuum between classic Mendelian and complex disease where the extremes, pure genetic or solely non-genetic, do not exist. The position of any given disease in this continuum is defined by three components: the major gene(s) contributing to the phenotype, the variability added by modifier genes and the significance of environmental factors influencing the phenotype. As the predictive value of genetic test results can be significantly influenced by additional genetic and environmental risk factors, a better understanding of these factors may influence the quantification of mortality and morbidity risk.  相似文献   
100.
We consider a semiparametric competing risk model given by k independent survival times. The paper offers an asymptotic treatment of tests for the semiparametric null hypothesis of equality of the underlying risks. It turns out that modified rank tests are asymptotically efficient for certain semiparametric submodels, where the baseline hazard is a nuisance parameter. In addition, the asymptotic relative efficiency of the present tests is derived. A comparison of asymptotic power functions can then be used to classify various tests proposed earlier in the literature. For instance a chi-square type test is efficient for proportional hazards. Data driven tests of likelihood ratio type are proposed for cones of alternatives. We will consider certain stochastically increasing alternatives as a special example. The paper shows how the concept of local asymptotic normality of Le Cam works for hazard oriented models.  相似文献   
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