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21.
Traditional timing models are affected by several biases, which generate spurious timing and stock-picking coefficients. Academics have appointed different causes as the possible sources of these biases. A negative correlation between timing and stock-picking abilities arises as a consequence of the biases in traditional timing models. This article provides evidence for one bias commonly found in traditional timing models, which is related with options. We focus on this bias in view of the scant attention it has so far received in the literature. We believe one possible cause for this bias is the failure to include the cost of the option implicit in timing activities in the timing models, and on this basis, we opt for a corrected version of the Merton and Henriksson model (1981 Merton, RC and Henriksson, RD. 1981. On market timing and investment performance II: statistical procedures for evaluating forecasting skills. Journal of Business, 54: 51334. [Crossref] [Google Scholar]). This study therefore is a pioneer in the assessment of the magnitude of this bias and in the measurement of the impact of its correction on fund managers’ results. Our results confirm both the existence of the bias and the correction of the problem when the cost of the option is included in timing models. The modified version of the Merton and Henriksson model, unlike the traditional model, reports positive timing and stock-picking coefficients, supporting the good performance by managers.  相似文献   
22.
Throughout much of mankind's experience with elections, vote brokers – local elites who direct the voting decisions of a subset of the electorate – have been able to make or break political careers. In various polities, brokers have thrived in spite of the secret ballot, a surprising outcome given that vote secrecy would ostensibly allow citizens to pocket the inducements offered by such individuals and vote their consciences anyway. To address this puzzle, we develop a framework for understanding the persistence and demise of vote brokerage under the secret ballot. In our model, a broker contracts with voters using an outcome contingent contract: some fixed benefit is promised to all voters sharing one of several observable profiles should the broker's candidate win the election. Using this framework, we demonstrate that the existence of brokerage depends on the size of the electorate contained within the jurisdiction controlled by the broker, with large jurisdiction sizes tending to drive brokerage out of existence. Moreover, we detail the manner in which the strategies employed by brokers depend on their economic power, the size of social groups, and ideological polarization. Empirical evidence from Minas Gerais, Brazil is used to evaluate the performance of the model.  相似文献   
23.
The severe consequences of a Critical Infrastructure (CI) crisis demand continued research directed toward proactive and reactive management strategies. Despite the best efforts of governments and communities, the diversity of stakeholders, conflicting demands for resources, and a lack of trust among organizations create complexities that limit the effectiveness of the response. This paper identifies four specific problems that appear to reoccur when CIs are challenged: heterogeneity, multiple and inconsistent boundaries, resilience building and knowledge transfer and sharing. A combination of collaborative modeling and software simulation methodologies is proposed in order to identify the interrelationships among diverse stakeholders when managing the preparation for and reaction to a CI crisis. This approach allows experts to work together and share experiences through the modeling process which can lead them to a better understanding of how other organizations work and integrate different perspectives. In addition, simulation models enable domain experts to understand the consequences of certain policies in the short and long terms, thus improving the crisis managers' knowledge for future crisis situations. This paper presents a practical case of a hypothetical crisis in the CI sector and the approach used in order to deal with the four problems identified above.  相似文献   
24.
The annual structure of the real GDP in the UK, France, Germany and Italy is examined by means of fractionally integrated techniques. Using a version of a testing procedure due to Robinson (Journal of the American Statistical Association, 84, –37, 1994), it is shown that the series can be specified in terms of I(d?) statistical models with d higher than 1. Thus, the series are nonstationary and non-mean-reverting. The forecasting properties of the selected models for each country are also examined.  相似文献   
25.
A model is estimated for the decision of participating in the labour market for different groups of household members: not coupled (single, divorced and widow) women and men and coupled (married and in permanent union) women and men. The differences among these groups are significant. Probit models are estimated for the period 1984?:?1–2000?:?4 using the National Housing Survey. The neoclassical static model performs fairly well in describing the empirical determinants of the decision of participating. In terms of sign and significance of estimated coefficients the best performance of the model is reached for women. In terms of prediction the model proves useful for not coupled persons. Except for the variable named ‘children aged less than six years’, all variables perform well.  相似文献   
26.
Two main factors underlie the rebirth of interest in the study of the influence of the real exchange rate on trade, the reduction of its volatility and the current trend towards price stability. The objective of this study is to analyse the effects of the process of nominal convergence, required of the European member states for the fulfilment of monetary integration, on foreign trade flows. The case of Spain, which is especially interesting in this context, is studied for the period 1986 to 2000. The results of estimating the aggregate functions of the export and import of goods shows how macroeconomic stability has altered the behaviour of trade with respect to the two basic determinants – income and prices – how it has caused a significant structural change in the real exchange rate and, finally, how it has laid the explanatory bases for transactions in the twenty-first century with the single currency – the euro.  相似文献   
27.
The aim of this study is to analyse labour productivity convergence in the OECD countries over the period 1975-90. A nonparametric frontier approach is used to calculate the Malmquist productivity index. By breaking it down, the contribution in the growth of labour productivity of technical progress, of changes in efficiency, and of the accumulation of inputs per worker are quantified. Unlike other studies, the results obtained show that technical change has worked against labour productivity convergence, since it has always been greater in the countries with higher labour productivity.  相似文献   
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29.
This article aims to quantify to what extent collaborative strategies are more effective than internal or organization‐level actions to green supply chains. In this regard, the impact of decisions made at different stages of a supply chain in a product's carbon footprint is quantified. Organizational and product carbon footprints are calculated using the Compound Method Based on Financial Accounts (MC3). The results underline that concentrating reduction efforts in some stages of the supply chain is more effective than implementing individual actions by the participants. Collaboration among the participants is needed to decide what practices are implemented, at what stage they are needed and how they are to be implemented. This article adds to the literature on supply chains and sustainability. Previous research suggests that collaborative strategies have great potential for reducing the carbon footprint of products, while indicating the need for empirical research to support this statement. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment  相似文献   
30.
Abstract. This paper examines the seasonal structure of German real GNP per capita by using a version of Robinson's (1994) tests which is suitable in the context of seasonality. This method has several advantages over alternative approaches when testing for seasonal unit roots. First, unlike standard tests, which are nested in AR alternatives, it is embedded in fractional alternatives. Second, it allows testing at the zero frequency and at each of the seasonal frequencies separately. Third, it makes it possible to test for different orders of integration at each of the frequencies simultaneously. The empirical analysis suggests that the real output series may have a unit root at the zero frequency, and fractional rather than unit roots at the seasonal ones. This is in contrast to the findings reported by Lutkepohl et al. (1999) in their study on German money demand, and shows the importance of modelling the seasonal features of the data in alternative ways.  相似文献   
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