首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   141051篇
  免费   3320篇
  国内免费   3篇
财政金融   26333篇
工业经济   11707篇
计划管理   22521篇
经济学   30412篇
综合类   1490篇
运输经济   987篇
旅游经济   2515篇
贸易经济   24596篇
农业经济   6184篇
经济概况   17253篇
信息产业经济   8篇
邮电经济   368篇
  2021年   881篇
  2020年   1688篇
  2019年   2465篇
  2018年   2562篇
  2017年   2727篇
  2016年   2893篇
  2015年   2221篇
  2014年   3538篇
  2013年   15659篇
  2012年   4442篇
  2011年   4381篇
  2010年   3904篇
  2009年   4494篇
  2008年   4091篇
  2007年   3420篇
  2006年   3658篇
  2005年   3656篇
  2004年   3183篇
  2003年   2971篇
  2002年   2906篇
  2001年   2748篇
  2000年   2642篇
  1999年   2516篇
  1998年   2397篇
  1997年   2426篇
  1996年   2293篇
  1995年   2081篇
  1994年   2063篇
  1993年   2039篇
  1992年   2084篇
  1991年   2004篇
  1990年   1890篇
  1989年   1701篇
  1988年   1636篇
  1987年   1654篇
  1986年   1729篇
  1985年   2496篇
  1984年   2371篇
  1983年   2165篇
  1982年   2024篇
  1981年   1953篇
  1980年   1921篇
  1979年   1854篇
  1978年   1650篇
  1977年   1639篇
  1976年   1406篇
  1975年   1299篇
  1974年   1202篇
  1973年   1197篇
  1972年   911篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
951.
We take as a starting point the existence of a joint distribution implied by different dynamic stochastic general equilibrium (DSGE) models, all of which are potentially misspecified. Our objective is to compare “true” joint distributions with ones generated by given DSGEs. This is accomplished via comparison of the empirical joint distributions (or confidence intervals) of historical and simulated time series. The tool draws on recent advances in the theory of the bootstrap, Kolmogorov type testing, and other work on the evaluation of DSGEs, aimed at comparing the second order properties of historical and simulated time series. We begin by fixing a given model as the “benchmark” model, against which all “alternative” models are to be compared. We then test whether at least one of the alternative models provides a more “accurate” approximation to the true cumulative distribution than does the benchmark model, where accuracy is measured in terms of distributional square error. Bootstrap critical values are discussed, and an illustrative example is given, in which it is shown that alternative versions of a standard DSGE model in which calibrated parameters are allowed to vary slightly perform equally well. On the other hand, there are stark differences between models when the shocks driving the models are assigned non-plausible variances and/or distributional assumptions.  相似文献   
952.
An earlier article, drawing on the mathematical theory of rules and rule complexes, extends and generalizes game theory (GGT). The theory has been used to conceptualize and analyze diverse social relationships, roles, and games as particular types of rule complexes.For instance, a social role, as a major basis of a parent's action in a game, consists of at least four key components – which are mathematical objects – in the determination of action: value complex, model of reality (including beliefs and knowledge bases), a repertoire of acts, routines, programs, and strategies, and modality, a role-specific algorithm for determining or generating action in game settings. This article applies and extends GGT in analyses of a market bargaining game (a type of open game) and of the classical game of prisoners' dilemma (a type of closed game). The applications show the concrete effects of social embeddedness on game structuring, game interaction patterns and outcomes, and social equilibria.  相似文献   
953.
In this paper characterizations of negative multinomial distributions based on conditional distributions have been studied.  相似文献   
954.
This paper presents an analytical approach to the tactical question: ‘What level of enforcement over time allows one to eliminate a street market for illicit drugs while expanding the least possible total effort?’ The analysis is done in the context of Caulkins' model [6] which predicts the rate of change of dealers as a function of enforcement level and several market parameters. Our analysis suggests that the simple strategy of using the maximum available enforcement intensity until the market has been eliminated minimizes the total enforcement effort required.  相似文献   
955.
Improving productive efficiency is an increasingly important determinant of the future of the swine industry in Hawaii. This paper examines the productive efficiency of a sample of swine producers in Hawaii by estimating a stochastic frontier production function and the constant returns to scale (CRS) and variable returns to scale (VRS) output-oriented DEA models. The technical efficiency estimates obtained from the two frontier techniques are compared. The scale properties are also examined under the two approaches. The industry's potential for increasing production through improved efficiency is also discussed.  相似文献   
956.
957.
We show that given a value function approximation V of a strongly concave stochastic dynamic programming problem (SDDP), the associated policy function approximation is Hölder continuous in V.  相似文献   
958.
Many textbooks on project management present illustrations concerning the relative size of project attributes during different project phases. The derived models all have attributes in common, such as uncertainty, significance of decisions, and degree of freedom to maneuver, that are typically high in the beginning of the project and low in the end. At the same time, variables such as the accumulated cost and available information begin at low levels and end up at a high level at the end of the project. Based on empirical data from projects, this paper illustrates and quantifies one of these attributes, the freedom to maneuver, in different project phases.  相似文献   
959.
Technological proximity and the choice of cooperation partner   总被引:1,自引:0,他引:1  
This paper provides empirical tests of hypotheses of cooperative behavior provided by evolutionary approaches in the resource-based view of the firm. The influences of “technological proximity”, individual incentives to cooperate and managerial tools to the choice of research partner are analyzed. Using German patent data we can show the positive influence of those three determinants. The results of this paper confirm theories dealing with the path-dependency of research activities.   相似文献   
960.
While it is well recognized that US metropolitan areas are polycentric, there is little consensus as to the appropriate method for identifying concentrations of employment within them. Existing methods suffer from strong assumptions about parametric form, misspecification, or reliance on local knowledge to calibrate model parameters. This paper introduces a new nonparametric method for identifying subcenters. Results indicate that this, more flexible, nonparametric approach yields greater accuracy with regard to both urban and suburban centers compared with other approaches. This approach should provide better data for the numerous topics that depend on the spatial accounting of employment within metropolitan areas.  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